—Could you do me a favor?—It depends on it is. A. whichB. whicheverC. whatD. whatever

问题补充：

—Could you do me a favor?

—It depends on it is.

A. which

B. whichever

C. what

D. whatever

答案：

A. which

B. whichever

(答案→)C. what

D. whatever

解析：介词on后面宾语从句不完整，同时从句缺少主语，故只能由what来充当。