Which sentence uses an adverbial phrase? a) the church youth group collected water bottles to recycle. b) the printers stopped working and refused to even power up. c) everyone needs to take his or her test in complete silence. d) all of the college kids booed the comedian for his bad jokes.

C) Everyone needs to take his or her test in complete silence.

Explanation:

An adverbial phrase is a group of words (two or more) that function as an adverb within a sentence. An adverbial phrase can modify verbs, adjectives or other adverbs in the same way that adverbs do. Moreover, just like adverbs, adverbial phrases respond to the question of how, why, where or when something was done. In this example, the phrase "in complete silence" describes HOW TO TAKE the test.

we need to see the examples!