The use of "keeping" in the sentence is incorrect, as "keeping" needs some version of the verb "to be" to form a functioning verb. (In the phrase "the soldiers keeping watch," "keeping" is a participle.) The verb must be changed to a form that can work in the sentence. The only choice that does this and keeps the intended meaning is "The soldiers keep watch."

The use of the participle "holding" means that there is no actual verb in the sentence. Not only does the form have to change, but the use of "came" later in the sentence means the verb form needs to be the past tense. "The tiny force held down the fort" is the only answer choice that uses the correct tense.

The use of the participle "obsessing" actually makes the sentence have no verb, as a participle cannot stand as a verb without some form of the verb "to be." "Obsessing" needs to be changed to an appropriate verb form to make the sentence complete. The only answer choice that uses a correct verb form is "The athlete obsessed over."

The use of the participle form "considering" in the sentence actually causes the sentence to not have a verb. A participle needs some form of the verb "to be" to make a complete verb phrase. "The child considered the model truck," which uses a simple past tense verb, is the only answer choice that corrects this issue.

The use of "keeping" as the only verb in the sentence is wrong, as "keeping" is a present participle, and a present participle always needs some form of the verb "to be" to precede it to create a verbal phrase. Additionally, the sentence needs to employ a past tense verb because its action takes place in the past. As such, the only answer choice that fulfills these requirements is "The old woman kept."

The verbal phrase "was astonishing" is structured as though the CEO is astonishing the company's finances. The only answer choice that fixes this issue is "The new CEO was astonished."

The use of "hoarding" makes the sentence contain no actual verb, as the present participle "hoarding" needs to be preceded by some form of the verb "to be" to make a complete verb phrase. "The woman was hoarding animals in unsafe conditions," is the only answer choice that inserts the appropriate word.

The use of "being" makes the sentence actually not have a verb, as "being" is a gerund, or a verb form that is used as a noun. The sentence needs to be changed so that it contains a verb. The only answer choice that corrects the issue is "are one of the best ways."

The use of the participle form "holding" makes the sentence actually have no practical verb, as a participle needs some form of the verb "to be" in order to function as the verb in the sentence. Either a version of "to be" needs to be put in the sentence, or "holding" should be changed to a proper verb form. "The young boy held onto his teddy bear" is the only answer choice that does either.

The use of the participle "creating" in the sentence makes the sentence not have a verb, as a participle needs some form of the verb "to be" to create a full verb for a sentence. Either the verb needs to be changed or have a form of "to be" added in. The only answer choice that does either is "The storm created havoc from the moment it made landfall near the coastal resort."