Which statement is true? an adverb can only modify a noun or a pronoun. some words that are usually nouns can function as adjectives. adverbs can modify adjectives, and adjectives can modify adverbs. an adjective is a word that modifies a verb, an adverb, or another adjective.

The second option is the correct one. "Some words that are usually nouns can function as adjectives."  It is true an adverb can modify an adjective, but an adjective cannot modify and adverb. The only option that doesn't mention an adjective modifying an adverb is the second one.

sight: watching a movie

touch: petting a dog

smell: smelling dinner

hearing: listening to music

taste: eating pizza

not sure maybe the subject closer to it or subject-verb agreement