English Accuplacer Practice Test

The term that properly modifies an adverb in this context is "more slowly." Adverbs provide information about verbs, adjectives, or other adverbs, often indicating a degree or manner of an action. "More slowly" is a comparative adverb, which means it shows a higher degree of the quality of being slow in the manner of an action. When modifying an adverb, it enhances the description of how something is done relative to other actions.

In contrast, the other options like "slower," "quick," and "fast" do not function as modifications to an adverb in the same comparative manner. "Slower" is a comparative form of the adjective "slow," which suggests a relative comparison but lacks the structure to modify an existing adverb efficiently. "Quick" and "fast" serve as adjectives or simple adverbs, but do not convey a comparative relationship that is necessary for modifying an adverb effectively. Therefore, "more slowly" stands out as the correct choice for modifying an adverb.