The correct statement is option B) “some words that are usually nouns can function as adjectives”. Sometimes nouns can function as adjectives depending on their placement within the sentence
Option A is incorrect since adjectives cannot modify adverbs.
Option C is also incorrect since an adjective only modifies nouns
Option D is also incorrect since adverbs do not modify nouns. Adverbs modify an adjective, a verb, a clause, and another adverb.