Evaluate Solutions for Ecosystem Impacts
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Biology › Evaluate Solutions for Ecosystem Impacts
An endangered frog is threatened by habitat loss and an introduced predatory fish that eats tadpoles. A conservation team proposes a combined plan: protect remaining pond habitat from development, remove the predatory fish from key breeding ponds, and breed frogs in captivity to release young frogs back into restored ponds.
Which evaluation best explains why this combined plan is more likely to succeed than captive breeding alone?
Because development near ponds does not affect frogs as long as the frogs are bred in captivity.
Because it addresses multiple limiting factors (habitat availability and predation) so released frogs have a higher chance of survival and reproduction.
Because captive breeding guarantees unlimited population growth even if habitat and predators remain unchanged in the wild.
Because removing fish is unnecessary if enough frogs are released at once to overwhelm predators permanently.
Explanation
This question tests your ability to evaluate proposed solutions for reducing human impacts on ecosystems by assessing their effectiveness (do they work?), feasibility (can they be implemented?), and sustainability (are they long-term solutions?). Evaluating ecosystem solutions requires considering multiple criteria: (1) EFFECTIVENESS: Addresses multiple ROOT CAUSES (habitat, predation) for better success? Evidence: integrated plans boost survival. (2) FEASIBILITY: Practical? (protection and removal achievable). (3) SUSTAINABILITY: Long-term? (restored habitats persist). BEST solutions comprehensive, trade-offs like effort. Combined plan effective (multi-factor), feasible, sustainable vs breeding alone (ignores limits). Choice B correctly explains success by addressing habitat and predation, improving survival and reproduction chances. Choice A fails by overstating breeding's guarantee without fixes; releases fail if threats remain—integrate solutions! The solution evaluation framework: (1) IDENTIFY PROBLEM: habitat loss, predation. (2) APPROACH: Combined PREVENTS/MITIGATES (best). (3) ROOT CAUSE: Multiple yes. (4) FEASIBILITY: Yes. (5) TRADE-OFFS: Effort vs recovery. Superb— holistic thinking wins!
A forested watershed supplies drinking water to a town. Logging on steep slopes has increased erosion, making the river muddy and raising water treatment needs. Two strategies are proposed:
Strategy A: Require logging companies to keep trees along stream banks (riparian buffers) and avoid logging steep slopes; replant native vegetation on eroding areas.
Strategy B: Build a larger water filtration plant to remove sediment from the drinking water after it reaches the intake.
Which statement best compares these strategies for long-term effectiveness and sustainability?
Strategy A cannot work because vegetation has no effect on erosion or water quality.
Both strategies are equally effective because sediment levels are determined only by natural river flow, not land practices.
Strategy B is more sustainable because it removes sediment after the damage occurs and does not require changes in land use.
Strategy A is more effective long-term because it reduces erosion at the source and helps restore watershed function, while Strategy B treats symptoms and may require ongoing costs and maintenance.
Explanation
This question tests your ability to evaluate proposed solutions for reducing human impacts on ecosystems by assessing their effectiveness (do they work?), feasibility (can they be implemented?), and sustainability (are they long-term solutions?). Evaluating ecosystem solutions requires considering multiple criteria: (1) EFFECTIVENESS: Does the solution address the ROOT CAUSE of the problem (preventing habitat destruction stops biodiversity loss at source) or just treat symptoms (replanting after continued deforestation doesn't solve underlying problem)? Solutions addressing causes are more effective than those treating effects. Does evidence show it works? (marine reserves demonstrably increase fish populations, protected areas reduce extinction rates—evidence-based solutions better than untested ideas). (2) FEASIBILITY: Is it practical to implement? (technically possible? affordable? socially acceptable?). Protecting existing habitat is often more feasible than restoring degraded habitat (prevention cheaper than restoration). (3) SUSTAINABILITY: Can it be maintained long-term without creating new problems? (renewable energy sustainable, fossil fuels not). The BEST solutions score well on all three criteria: effective at reducing impact, feasible to implement, sustainable long-term—though trade-offs are common (highly effective solutions might be expensive, easily implemented solutions might only partially address problem). The problem is erosion from logging causing muddy water. Strategy A addresses the ROOT CAUSE by preventing erosion through riparian buffers and avoiding steep slopes (where erosion is worst), plus restoration of eroding areas. This is watershed protection—proven effective worldwide. Strategy B only treats the SYMPTOM by filtering muddy water after erosion occurs, while erosion continues damaging the watershed. Effectiveness: Strategy A reduces erosion at the source protecting water quality naturally; Strategy B cleans already-damaged water while watershed degradation continues. Feasibility: Both are feasible, but preventing erosion is ultimately cheaper than perpetual treatment. Sustainability: Strategy A restores natural watershed function (self-maintaining once vegetation established); Strategy B requires ongoing operation costs, energy, and maintenance forever. Choice B correctly evaluates that Strategy A is more effective long-term because it reduces erosion at the source and helps restore watershed function, while Strategy B treats symptoms with ongoing costs—this recognizes that ecosystem-based solutions addressing root causes are more sustainable than technological fixes treating symptoms. Choice A wrongly claims removing sediment after damage is more sustainable (opposite—prevention is more sustainable), Choice C incorrectly states vegetation has no effect on erosion (vegetation is crucial for erosion control), and Choice D falsely claims only river flow determines sediment (land use practices are major drivers of erosion and sedimentation).
A coastal fish species has declined due to overharvesting. Managers are considering two approaches:
Approach A: Set a science-based annual catch limit (quota) and require reporting and monitoring to keep harvest near the population’s replacement rate.
Approach B: Allow unlimited fishing but require fishers to release any fish smaller than a set length.
Which statement best evaluates the two approaches for effectiveness and feasibility?
Both approaches are equally effective because fish populations always rebound quickly regardless of harvest rate.
Approach A is not scientifically sound because any quota will eventually drive the population to extinction.
Approach B is more effective because size limits alone prevent overharvesting even if total catch is unlimited.
Approach A is more likely to stabilize the population because it directly limits total removals, but it requires enforcement and accurate monitoring to be feasible.
Explanation
This question tests your ability to evaluate proposed solutions for reducing human impacts on ecosystems by assessing their effectiveness (do they work?), feasibility (can they be implemented?), and sustainability (are they long-term solutions?). Evaluating ecosystem solutions requires considering multiple criteria: (1) EFFECTIVENESS: Does the solution address the ROOT CAUSE of the problem (preventing habitat destruction stops biodiversity loss at source) or just treat symptoms (replanting after continued deforestation doesn't solve underlying problem)? Solutions addressing causes are more effective than those treating effects. Does evidence show it works? (marine reserves demonstrably increase fish populations, protected areas reduce extinction rates—evidence-based solutions better than untested ideas). (2) FEASIBILITY: Is it practical to implement? (technically possible? affordable? socially acceptable?). Protecting existing habitat is often more feasible than restoring degraded habitat (prevention cheaper than restoration). (3) SUSTAINABILITY: Can it be maintained long-term without creating new problems? (renewable energy sustainable, fossil fuels not). The BEST solutions score well on all three criteria: effective at reducing impact, feasible to implement, sustainable long-term—though trade-offs are common (highly effective solutions might be expensive, easily implemented solutions might only partially address problem). The fish population declined from overharvesting—too many fish being removed. Approach A uses science-based quotas to limit total catch to the population's replacement rate, directly addressing the ROOT CAUSE (too much harvest). This is effective IF properly enforced and monitored. Approach B only protects small fish but allows unlimited total catch—this doesn't control overall harvest rate, so overfishing can continue on larger fish. Effectiveness: A directly limits removals to sustainable levels; B doesn't control total harvest. Feasibility: A requires monitoring and enforcement infrastructure (challenging but doable); B is easier to implement but less effective. Sustainability: A maintains population if quotas are science-based; B may still allow population decline. Choice B correctly evaluates that Approach A is more likely to stabilize the population because it directly limits total removals, while acknowledging the feasibility challenge of enforcement and monitoring—this shows understanding of both effectiveness and trade-offs. Choice A wrongly claims size limits alone prevent overharvesting (they don't control total catch), Choice C incorrectly states any quota drives extinction (science-based quotas allow sustainable harvest), and Choice D falsely claims fish always rebound quickly (many overfished populations take decades to recover or don't recover at all).
A deer population in a suburban park has grown so large that it is over-browsing young trees, preventing forest regeneration. Managers propose allowing a limited annual harvest (controlled hunting) based on population surveys.
Which statement best describes a key challenge to making this strategy sustainable and effective?
The strategy will fail because harvesting can never reduce a population; it only increases birth rates immediately
The strategy is unnecessary because over-browsing always improves forest biodiversity by creating open space
The strategy is sustainable only if all predators are removed first to prevent double mortality
The strategy can work, but it requires accurate monitoring and enforcement so the harvest rate does not exceed the population’s ability to replace individuals
Explanation
This question tests your ability to evaluate proposed solutions for reducing human impacts on ecosystems by assessing their effectiveness (do they work?), feasibility (can they be implemented?), and sustainability (are they long-term solutions?). Evaluating ecosystem solutions requires considering multiple criteria: Wildlife population management through controlled harvest is a complex conservation tool. (1) EFFECTIVENESS: Reducing deer density can allow forest regeneration if harvest rates are carefully calibrated to population growth rates. Too little harvest won't reduce browsing pressure; too much could crash the population. (2) FEASIBILITY: Requires accurate population monitoring, setting appropriate quotas, and enforcement—all technically possible but requiring ongoing resources. (3) SUSTAINABILITY: Can be maintained long-term if harvest rates match population replacement rates. The key challenge: Problem = overabundant deer preventing forest regeneration. Solution = controlled harvest to reduce population. Success depends critically on accurate monitoring and adaptive management. Choice B correctly identifies the key challenge: harvest rates must not exceed the population's ability to replace individuals through reproduction—this recognizes that sustainable harvest requires careful balance between removal and population growth. Choice A incorrectly claims harvesting can never reduce populations—controlled harvest is successfully used worldwide to manage wildlife populations when removal exceeds birth rates. The solution evaluation framework shows that population management through harvest can be effective and sustainable, but requires scientific monitoring, adaptive management based on population response, and enforcement to prevent overharvest—highlighting that ecosystem solutions often succeed or fail based on implementation details rather than the concept itself.
A community wants to reduce plastic pollution that harms seabirds and turtles. Two strategies are proposed:
Strategy A: Install floating trash-capture booms at the mouth of a river to collect plastic already moving toward the ocean.
Strategy B: Reduce plastic at the source by switching to reusable containers in schools and businesses and improving waste collection to prevent litter.
Which statement best compares the strategies for long-term impact reduction?
Strategy A and B are equally effective because plastic harms wildlife only after it reaches deep ocean trenches
Strategy A is more effective long-term because capturing trash after it enters the river prevents plastic production
Strategy B is more effective long-term because it reduces the amount of plastic entering the environment, while Strategy A mainly treats symptoms and requires ongoing maintenance
Strategy B will fail unless all existing plastic in the ocean is removed first
Explanation
This question tests your ability to evaluate proposed solutions for reducing human impacts on ecosystems by assessing their effectiveness (do they work?), feasibility (can they be implemented?), and sustainability (are they long-term solutions?). Evaluating ecosystem solutions requires considering multiple criteria: This comparison clearly illustrates prevention versus mitigation approaches to pollution. (1) EFFECTIVENESS: Strategy B reduces plastic production and entry into environment (addresses root cause), while Strategy A captures some plastic after it's already become litter (treats symptom). Not all plastic reaches capture points—much escapes to ocean. (2) FEASIBILITY: Both are feasible—reusable containers and better waste management are proven solutions; trash booms work but capture only a fraction of plastic. (3) SUSTAINABILITY: Source reduction provides permanent decrease in plastic waste; capture booms require constant maintenance and removal of collected trash. Evaluating strategies: Problem = plastic pollution harming marine life. Root cause = plastic production and improper disposal. Strategy B prevents plastic from entering environment (addresses cause), Strategy A captures some plastic after littering (treats symptom). Choice B correctly identifies that Strategy B is more effective long-term because it reduces plastic entering the environment at the source, while Strategy A treats symptoms and requires ongoing maintenance—this recognizes the superiority of prevention over end-of-pipe solutions. Choice A incorrectly claims capturing trash prevents plastic production—removing plastic from rivers doesn't stop new plastic from being produced and discarded. The solution evaluation framework confirms that source reduction (prevent plastic use and littering) beats end-of-pipe treatment (capture plastic in rivers) because it addresses the root cause of plastic pollution, reduces the total amount of plastic in the system, and doesn't rely on capturing every piece of plastic before it reaches the ocean.
A coral reef is declining due to warming ocean temperatures and local pollution from sewage. Two actions are proposed:
Action 1: Upgrade sewage treatment to reduce nutrients and pathogens entering the reef.
Action 2: Build shaded floating structures over parts of the reef to reduce sunlight and water temperature locally.
Which evaluation is most accurate about addressing the causes of reef decline?
Action 1 is likely feasible and helps reduce a local stressor at the source, but it will not fully solve warming-driven bleaching without broader climate mitigation
Action 1 is unnecessary because sewage nutrients increase coral growth and always improve reef health
Action 2 is best long-term because shading fixes global warming by cooling the entire ocean
Both actions are ineffective because coral reefs cannot recover once any bleaching occurs
Explanation
This question tests your ability to evaluate proposed solutions for reducing human impacts on ecosystems by assessing their effectiveness (do they work?), feasibility (can they be implemented?), and sustainability (are they long-term solutions?). Evaluating ecosystem solutions requires considering multiple criteria: Coral reefs face both global (climate change) and local (pollution) stressors requiring different approaches. (1) EFFECTIVENESS: Action 1 reduces local stressors (nutrients and pathogens) that compound warming stress—corals facing fewer stressors are more resilient. Action 2 attempts to reduce local temperature but doesn't address the global warming trend. (2) FEASIBILITY: Sewage treatment upgrades use proven technology; building floating structures over reefs is experimental and could have unintended consequences (reduced light might harm coral photosynthesis). (3) SUSTAINABILITY: Improved sewage treatment provides lasting benefits; shading structures require maintenance and don't address root causes. Evaluating actions against reef threats: Reefs face warming (global) plus pollution (local). Action 1 reduces local stressors, improving reef resilience to warming. Action 2 treats temperature symptoms locally without addressing causes. Choice B correctly recognizes that Action 1 is feasible and reduces local stressors at the source, while acknowledging it cannot fully solve warming-driven bleaching without climate action—this honest assessment recognizes both the value and limitations of local action. Choice A incorrectly claims shading fixes global warming—local shading cannot address ocean-wide temperature increases driven by atmospheric CO2. The solution evaluation framework shows that addressing manageable local stressors (pollution) while working on global challenges (climate change) represents realistic conservation: we can't solve everything locally, but reducing cumulative stress improves ecosystem resilience.
A region wants to reduce climate-related ecosystem stress (heat waves, drought, shifting species ranges). Two actions are proposed: Action A replaces coal electricity with wind and solar over the next decade. Action B builds shaded wildlife feeding stations in several parks to help animals during heat waves. Which evaluation is most accurate?
Both actions are equally effective because any help to individual animals automatically stabilizes global climate patterns.
Action A addresses a root cause by reducing greenhouse gas emissions, while Action B may help locally but does not reduce climate change drivers.
Action A is ineffective because renewable energy cannot reduce carbon dioxide once it is in the atmosphere.
Action B is more effective because it directly cools the entire region and reverses global warming.
Explanation
This question tests your ability to evaluate proposed solutions for reducing human impacts on ecosystems by assessing their effectiveness (do they work?), feasibility (can they be implemented?), and sustainability (are they long-term solutions?). Evaluating ecosystem solutions requires considering multiple criteria: (1) EFFECTIVENESS: Does the solution address the ROOT CAUSE of the problem (preventing habitat destruction stops biodiversity loss at source) or just treat symptoms (replanting after continued deforestation doesn't solve underlying problem)? Solutions addressing causes are more effective than those treating effects. Does evidence show it works? (marine reserves demonstrably increase fish populations, protected areas reduce extinction rates—evidence-based solutions better than untested ideas). (2) FEASIBILITY: Is it practical to implement? (technically possible? affordable? socially acceptable?). Protecting existing habitat is often more feasible than restoring degraded habitat (prevention cheaper than restoration). (3) SUSTAINABILITY: Can it be maintained long-term without creating new problems? (renewable energy sustainable, fossil fuels not). The BEST solutions score well on all three criteria: effective at reducing impact, feasible to implement, sustainable long-term—though trade-offs are common (highly effective solutions might be expensive, easily implemented solutions might only partially address problem). Climate stress from emissions affects ecosystems broadly, so renewables address global root causes while shaded stations provide local symptom relief, evaluating for scale and long-term impact. Choice A accurately evaluates Action A as addressing emissions root cause, contrasting with B's local but non-preventive help. Choice B fails by overclaiming shaded stations reverse global warming, confusing local aid with climate driver reduction. The solution evaluation framework: (1) IDENTIFY the PROBLEM clearly: What's the ecosystem impact? (habitat loss, pollution, overfishing, climate change). (2) IDENTIFY the SOLUTION'S approach: Does it PREVENT (stop the damaging activity—best if feasible), MITIGATE (reduce severity of activity—good compromise), or REPAIR (fix damage after—least effective but sometimes necessary)? Prevention > Mitigation > Repair in effectiveness hierarchy. (3) CHECK if it addresses ROOT CAUSE: Example: Problem = lake eutrophication (algal blooms). Root cause = fertilizer runoff. Solution addressing cause: reduce fertilizer use, create buffer zones (prevents runoff). Solution treating symptom: remove algae manually (doesn't stop blooms, they return). Cause-focused solutions more effective! (4) EVALUATE feasibility: Is it technically possible? (do we know how?). Is it affordable? (can it be funded?). Is it socially/politically acceptable? (will people support it?). Solutions fail if not feasible even if effective in theory. (5) CONSIDER trade-offs: What are costs (economic, social)? What are benefits (environmental, long-term economic)? Are trade-offs acceptable? No solution is free or perfect—honest evaluation acknowledges both upsides and downsides! This comparison shows how evaluating against criteria reveals solution quality, prioritizing emission reductions for climate—superb analysis!
A wetland was drained decades ago for agriculture, causing increased downstream flooding and loss of amphibian habitat. A restoration plan would plug drainage ditches, replant native wetland vegetation, and allow seasonal flooding to return. Which outcome best supports the claim that this restoration is effective and scientifically sound?
Crop yields increase on the drained wetland area after restoration, showing the wetland has fully recovered.
Amphibians decrease but algae increases, showing restoration always improves biodiversity.
Flooding increases downstream because water moves faster through the restored wetland, proving wetlands do not store water.
Amphibian populations increase and downstream peak flood levels decrease after restoration, indicating improved habitat and water storage.
Explanation
This question tests your ability to evaluate proposed solutions for reducing human impacts on ecosystems by assessing their effectiveness (do they work?), feasibility (can they be implemented?), and sustainability (are they long-term solutions?). Evaluating ecosystem solutions requires considering multiple criteria: (1) EFFECTIVENESS: Does the solution address the ROOT CAUSE of the problem (preventing habitat destruction stops biodiversity loss at source) or just treat symptoms (replanting after continued deforestation doesn't solve underlying problem)? Solutions addressing causes are more effective than those treating effects. Does evidence show it works? (marine reserves demonstrably increase fish populations, protected areas reduce extinction rates—evidence-based solutions better than untested ideas). (2) FEASIBILITY: Is it practical to implement? (technically possible? affordable? socially acceptable?). Protecting existing habitat is often more feasible than restoring degraded habitat (prevention cheaper than restoration). (3) SUSTAINABILITY: Can it be maintained long-term without creating new problems? (renewable energy sustainable, fossil fuels not). The BEST solutions score well on all three criteria: effective at reducing impact, feasible to implement, sustainable long-term—though trade-offs are common (highly effective solutions might be expensive, easily implemented solutions might only partially address problem). The wetland restoration aims to reverse drainage effects like flooding and habitat loss, so effective outcomes should show improved biodiversity and water functions, based on scientific indicators. Choice A correctly supports effectiveness with increased amphibians and decreased floods, evidencing habitat and storage recovery. Choice B fails by citing crop yield increases, which contradict restoration goals of returning to wetland, not agriculture. The solution evaluation framework: (1) IDENTIFY the PROBLEM clearly: What's the ecosystem impact? (habitat loss, pollution, overfishing, climate change). (2) IDENTIFY the SOLUTION'S approach: Does it PREVENT (stop the damaging activity—best if feasible), MITIGATE (reduce severity of activity—good compromise), or REPAIR (fix damage after—least effective but sometimes necessary)? Prevention > Mitigation > Repair in effectiveness hierarchy. (3) CHECK if it addresses ROOT CAUSE: Example: Problem = lake eutrophication (algal blooms). Root cause = fertilizer runoff. Solution addressing cause: reduce fertilizer use, create buffer zones (prevents runoff). Solution treating symptom: remove algae manually (doesn't stop blooms, they return). Cause-focused solutions more effective! (4) EVALUATE feasibility: Is it technically possible? (do we know how?). Is it affordable? (can it be funded?). Is it socially/politically acceptable? (will people support it?). Solutions fail if not feasible even if effective in theory. (5) CONSIDER trade-offs: What are costs (economic, social)? What are benefits (environmental, long-term economic)? Are trade-offs acceptable? No solution is free or perfect—honest evaluation acknowledges both upsides and downsides! This comparison shows how evaluating against criteria reveals solution quality, using measurable outcomes for wetlands—excellent verification skills!
A river downstream of a factory has elevated levels of a toxic metal in sediments. Two cleanup proposals are discussed:
Proposal 1: Install improved filtration at the factory to stop metal discharge and monitor water quality monthly.
Proposal 2: Dredge (remove) contaminated sediments from the riverbed but make no changes at the factory.
Which evaluation is most scientifically sound?
Proposal 2 is best because removing sediments eliminates the need to change factory practices and permanently solves the problem.
Proposal 1 is essential because it prevents ongoing pollution at the source; dredging alone may be temporary if contamination continues.
Proposal 2 is most sustainable because it treats symptoms in the ecosystem rather than changing the human activity causing pollution.
Neither proposal can reduce metal levels because toxic metals cannot be controlled by human actions once released.
Explanation
This question tests your ability to evaluate proposed solutions for reducing human impacts on ecosystems by assessing their effectiveness (do they work?), feasibility (can they be implemented?), and sustainability (are they long-term solutions?). Evaluating ecosystem solutions requires considering multiple criteria: (1) EFFECTIVENESS: Addresses ROOT CAUSE (stopping discharge prevents buildup) vs symptoms (dredging removes but allows recurrence)? Cause-focused better. Evidence: filtration reduces pollutants. (2) FEASIBILITY: Practical? (installation feasible). (3) SUSTAINABILITY: Long-term? (prevention ongoing). BEST solutions strong in all, trade-offs like costs. Proposal 1 is effective (prevents), feasible (monitoring), sustainable (stops ongoing), while 2 is temporary. Choice B correctly evaluates Proposal 1 as essential for preventing pollution at source, noting dredging's temporariness if discharge continues. Choice A fails by claiming dredging permanently solves without source changes, but contamination would resume—always target the source! The solution evaluation framework: (1) IDENTIFY PROBLEM: metal pollution from factory. (2) APPROACH: 1 PREVENTS (best), 2 REPAIRS (limited). (3) ROOT CAUSE: 1 yes. (4) FEASIBILITY: Both possible, 1 more sustainable. (5) TRADE-OFFS: Initial cost vs clean river. Keep it up— you're evaluating like an expert!
A coral reef is declining due to warming ocean temperatures that cause coral bleaching. A local community proposes two actions:
Action A: Build artificial reef structures (concrete blocks) to provide habitat for fish.
Action B: Reduce local greenhouse gas emissions by switching municipal electricity to renewable sources and improving energy efficiency.
Which statement best compares the actions for addressing the main cause of coral bleaching?
Action A addresses the main cause because fish habitat is the primary driver of coral bleaching.
Both actions address the main cause equally because any habitat improvement automatically prevents temperature stress.
Action B more directly addresses the main cause by reducing contributions to climate warming, though local actions alone may not fully stop global temperature rise.
Action A is more effective long‑term because concrete reefs cool the water and prevent bleaching.
Explanation
This question tests your ability to evaluate proposed solutions for reducing human impacts on ecosystems by assessing their effectiveness (do they work?), feasibility (can they be implemented?), and sustainability (are they long-term solutions?). Evaluating ecosystem solutions requires considering multiple criteria: (1) EFFECTIVENESS: Addresses ROOT CAUSE (reducing emissions fights warming) vs unrelated (artificial reefs don't cool water)? Evidence: renewables lower GHGs. (2) FEASIBILITY: Practical locally? (yes for energy switches). (3) SUSTAINABILITY: Long-term? (reduces climate impact). BEST solutions align, trade-offs like scale. Action B effective (targets warming), feasible (local), sustainable, though global needed; A doesn't address cause. Choice B correctly compares by noting Action B addresses climate warming directly, with limitation that local actions contribute but don't fully halt global rise. Choice A fails by misidentifying habitat as main cause; bleaching is temperature-driven—focus on causes! The solution evaluation framework: (1) IDENTIFY PROBLEM: warming causing bleaching. (2) APPROACH: B PREVENTS (best), A unrelated. (3) ROOT CAUSE: B yes. (4) FEASIBILITY: B achievable. (5) TRADE-OFFS: Local vs global scale. Awesome progress— think globally, act locally!