—How long are you staying?I don’t know. A. That’s OK. B Never mind.C. It all depends. D

问题补充：

—How long are you staying?

--I don’t know.

A. That’s OK. B Never mind.

C. It all depends. D. It doesn’t matter.

答案：

解析：句意：你要呆多久？我不知道，要看情况而定。 It all depends.视情况而定，所以选C。