Which sentence contains an adverbial phrase? The hopeful actors agreed to meet in the dressing room before the audition. The persistent rain left large, rippling puddles and soggy front lawns. The ongoing delay really infuriated the cranky, grumbling audience. The oblivious pedestrian encountered loud car horns blaring at him.

The sentence that contains an adverbial phrase is the first one - The hopeful actors agreed to meet in the dressing room before the audition. The phrase before the audition is adverbial, because it shows the time something happened.

The correct answer is - The hopeful actors agreed to meet in the dressing room before the audition.

The phrases in the dressing room and before the audition are adverbial phrases in this sentence. The first phrase denotes the place, whereas the second one denotes the time. Place, time, manner, etc. are all adverbial meanings, so these two are adverbial phrases. There are no adverbial phrases in the remaining sentences.