PLEASE HELP ASAP 50 POINTS
Read the sentence.


Yesterday, when they arrived at the beach, the students who had never seen the ocean before were surprised by the size of the foaming waves that rolled gracefully toward the shore.

Which part of the sentence is an adverbial dependent clause?


A: when they arrived at the beach

B: who had never seen the ocean before

C: by the size of the foaming waves

D: that rolled gracefully toward the shore