What is the function of an adverb in a sentence?

The function of an adverb in a sentence is to modify verbs, adjectives, or other adverbs, which is precisely what the correct answer states. Adverbs provide additional information about how an action is performed, to what extent an adjective applies, or how another adverb modifies a verb. For example, in the sentence “She quickly runs,” the adverb “quickly” modifies the verb “runs” by explaining how she runs. Similarly, in “He is very tall,” the adverb “very” modifies the adjective “tall,” indicating the degree of tallness. This flexibility in modifying various parts of speech is a fundamental characteristic of adverbs, highlighting their critical role in adding detail and nuance to sentences.