Meaning: 'Matter' refers to a subject or situation that is important or significant.

Wrong options:

• concern: 'Concern' implies worry or interest but does not fit the grammatical structure as well as 'matter' does in this context.
• business: 'Business' suggests a commercial aspect, which does not align with the context of human intention regarding domestication.
• point: 'Point' refers to a specific detail or argument, which does not capture the broader significance of domestication as effectively as 'matter'.

Correct answer: granted

Explanation: The word 'granted' is used here to indicate something that is accepted as true or taken for granted. It fits contextually as it reflects the idea that certain traits of the horse are assumed to be inherent.

Meaning: 'Granted' means accepted or acknowledged without question, often implying that something is taken as a given.

Wrong options:

• assumed: 'Assumed' suggests a belief without proof, but 'granted' carries a stronger connotation of acceptance.
• given: 'Given' implies something that is provided, which does not convey the same sense of acceptance as 'granted'.
• read: 'Read' refers to interpreting written text, which is unrelated to the context of accepting traits of the horse.

Correct answer: undergone

Explanation: The word 'undergone' is the past participle of 'undergo', which means to experience or endure something. It fits grammatically and contextually as it describes the evolutionary changes that the horse has experienced.

Meaning: 'Undergone' means to have gone through or experienced a process or change.

Wrong options:

• subjected: 'Subjected' implies being forced to undergo something, which does not fit the context of natural evolutionary changes.
• submitted: 'Submitted' suggests a voluntary action of yielding, which does not accurately describe the evolutionary process.
• committed: 'Committed' implies a promise or dedication, which is not relevant to the context of evolutionary changes.

Correct answer: compelled

Explanation: The word 'compelled' indicates being forced or driven to act in a certain way. It fits grammatically and contextually as it describes how herbivores had to change their diets due to environmental changes.

Meaning: 'Compelled' means to be forced or driven to do something.

Wrong options:

• coerced: 'Coerced' implies force through threats, which is too strong for the context of dietary changes.
• enforced: 'Enforced' suggests a rule or law being applied, which does not fit the natural context of dietary adaptation.
• necessitated: 'Necessitated' implies that something is made necessary, but it lacks the direct implication of force that 'compelled' conveys.

Correct answer: grew

Explanation: The word 'grew' is the past tense of 'grow', which indicates an increase in size. It fits grammatically and contextually as it describes the physical change in the horse's head.

Meaning: 'Grew' means to increase in size or develop.

Wrong options:

• exapanded: 'Exapanded' is a misspelling of 'expanded', which means to increase in size but does not fit the grammatical structure.
• increased: 'Increased' is a synonym for 'grew', but it does not fit as naturally in this context as 'grew' does.
• enlarged: 'Enlarged' suggests a more artificial increase in size, which does not accurately describe the natural growth process.

Correct answer: lookout

Explanation: The word 'lookout' refers to a watchful observation for danger. It fits contextually as it describes the horse's need to be vigilant while grazing.

Meaning: 'Lookout' means a person or thing that watches for danger or trouble.

Wrong options:

• need: 'Need' refers to a requirement, which does not fit the context of actively watching for predators.
• vigilance: 'Vigilance' is a state of being watchful, but it does not fit grammatically as a noun in this context.
• alert: 'Alert' is an adjective describing a state of readiness, which does not fit as a noun in this context.