Choose the best answer.

Which sentence correctly identifies an adverb clause?

A. Does the boy "whose kite we borrowed" live in the cottage across the street?

B. That bracelet, "which is made of sterling silver," has a delicate clasp.

C. "Before we left the camping grounds," we noticed a sign for the scenic trail.

D. The stuffed plush bear "that Randall bought for his baby brother" is soft.

(The "" represents the adverb clause)