A "greyhound" is a dog that is primarily bred and used for "racing." So, to solve this analogy you need to figure out what it is that a "retriever" is used for. Well, the clue is in the name, "retrievers" retrieve things. The correct answer is therefore "fetching," which means to go and get something and bring it back.

An "inoculation" is a vaccination, a small amount of a "disease" injected into someone to prevent them from contracting a much more serious version of the "disease." So, the purpose of an "inoculation" is to prevent "disease." What is the purpose of a "levee?" Well, a "levee" is a wall or embankment built to stop the overflow of water. So, the correct answer is that it prevents "flooding."

A "laboratory" is a lab, a place where scientific experiments are conducted. The purpose of a "laboratory" then is to carry out "experiments." What is the purpose of an "amphitheater?" Well, an "amphitheater" is a round and open building where sporting events or plays are carried out, particularly in regard to Ancient Greece or Rome. The correct answer then is "entertain." Additionally, "nourish" means provide food or energy for; "gripe" means complain about something small or unimportant, find fault with; "inhibit" means prevent from doing; "imprison" means confine, lock up.

"Krill" are small animals that float in large numbers in the ocean. Many "whales" eat "krill." So, to solve this analogy you need to determine which of these is something that "cows" eat. The correct answer is "grass."

"Taxidermy" is the process of preparing and "stuffing" animals after they have died. So, "stuffing" is involved in "taxidermy," which of the following is involved in "cremation?" Well, "cremation" is the act of "burning" a body for the purposes of burial. So, the correct answer is "burning."

An "autopsy" is an examination of a "corpse" to discover how someone died. A "corpse" is a dead body. So, which of these is an examination of the "population?" The correct answer is a "census." In the United States a "census" is conducted every ten years, it involves a series of questions asked by the government to try and determine the nature of the current population. Additionally, a "morgue" is a place where dead bodies are held before they are buried.

A "diner" is a restaurant, somewhere you go to "eat." So, to solve this analogy you need to determine what someone might go to an "academy" to do. Well, an "academy" is a place to study something or practice for something. So, the correct answer is "learn." Additionally, "conspire" means plot with someone else to commit illegal acts.

A dentist is a professional who studies and works with an individual's teeth. While all of the choices have associations with occupations, a cardiologist is a professional who studies and works with an individual's heart, making it the correct answer.

A "maestro" is the conductor of an orchestra. Just as a director organizes and directs actors in a production, a maestro directs an orchestra. The rest of the answer options refer to groups, but not the leaders of those groups.

A "pilot" is someone who operates a piece of machinery, (usually) someone who flies a plane. So, an action undertaken by a "pilot" is to "fly," which of these is an action undertaken by a "mariner"? Well, a "mariner" is a sailor, so the correct answer is "sail."