Which words in the sentence are the adverb clause?

Wait with your friend near the front of the store while I finish grocery shopping.

a. while I finish grocery shopping

b. near the front of the store

c. Wait with your friend

The correct answer is A. While I finish grocery shopping is a temporal clause, that is, a clause of time, or the adverbial clause of time. B cannot be the correct answer because this is not a clause - it doesn't have a verb so it cannot be a clause, it is just an adverbial phrase. C is also not the correct answer since it is not an adverbial clause, it is just a regular sentence in the imperative form.