The young calf became |quite| frightened, so it called |veryloudly| for its mother. Which underlined adverb modifies a verb? A. loudly B. very C. quite

Option A is correct that is loudly.

The adverb that modifies a verb is A. loudly.

Although there are three adverbs in this sentence, the word loudly is the only one that modifies a verb, which is called.

The other two adverbs are quite, which modifies the adjective frightened, and the word very, which modifies the adverb loudly.