A.I. Explanation:

Correct answer: seasonally

Explanation: The word 'seasonally' is an adverb that describes how the diet varies according to different seasons. This fits grammatically as it modifies the verb 'varies' and aligns with the context of discussing changes in diet throughout the year.

Meaning: 'Seasonally' means occurring or changing at different times of the year.

Wrong options:

• lately: Lately is an adverb indicating a recent time period, which does not relate to the seasonal variation of diet.
• decision: Decision is a noun that refers to a choice made, which does not fit grammatically or contextually in this sentence.
• establish: Establish is a verb that means to set up or create, which does not relate to the variation of diet.
• preference: Preference is a noun that indicates a greater liking for one option over another, which does not fit the context of diet variation.
• dense: Dense is an adjective that describes something that is closely packed together, which does not apply to the variation of diet.
• complicated: Complicated is an adjective that means difficult to understand or deal with, which does not fit the context of diet variation.

Correct answer: establish

Explanation: The verb 'establish' fits grammatically as it indicates the action martens take in creating or setting up their home ranges. This aligns with the context of discussing how martens interact with their environment.

Meaning: 'Establish' means to set up or create something in a particular place.

Wrong options:

• lately: Lately is an adverb that does not fit as it does not describe an action related to home ranges.
• decision: Decision is a noun and does not fit grammatically as it does not describe an action taken by martens.
• seasonally: Seasonally is an adverb that describes timing, which does not fit the context of establishing home ranges.
• preference: Preference is a noun that indicates a choice, which does not relate to the action of establishing home ranges.
• dense: Dense is an adjective that describes a physical characteristic, which does not apply to the action of establishing.
• complicated: Complicated is an adjective that does not describe an action and does not fit in this context.

Correct answer: dense

Explanation: The adjective 'dense' describes the type of shrubs in which martens establish their home ranges. It fits grammatically as it modifies the noun 'shrubs' and is contextually appropriate as it describes the environment preferred by martens.

Meaning: 'Dense' means closely packed together or thick, often used to describe vegetation.

Wrong options:

• lately: Lately is an adverb that does not describe a physical characteristic of shrubs.
• decision: Decision is a noun that does not fit as it does not describe the type of shrubs.
• seasonally: Seasonally is an adverb that does not apply to the description of shrubs.
• preference: Preference is a noun that indicates a choice, which does not fit the context of describing shrubs.
• establish: Establish is a verb that does not describe a characteristic of shrubs and does not fit grammatically.
• complicated: Complicated is an adjective that means difficult to understand, which does not apply to the description of shrubs.

Correct answer: preference

Explanation: The noun 'preference' fits grammatically as it serves as the subject of the clause, indicating what is shown regarding martens' selection of Microtus voles over other small mammals. This aligns with the context of discussing dietary choices.

Meaning: 'Preference' refers to a greater liking for one option over another.

Wrong options:

• lately: Lately is an adverb that does not fit as it does not describe a choice or selection.
• decision: Decision is a noun that refers to a choice made, but it does not fit the context of showing a selective behavior.
• seasonally: Seasonally is an adverb that does not relate to the concept of preference in dietary choices.
• establish: Establish is a verb that does not fit grammatically as it does not describe a noun related to selection.
• dense: Dense is an adjective that describes a physical characteristic and does not fit the context of preference.
• complicated: Complicated is an adjective that does not relate to the concept of preference and does not fit grammatically.