You were rude to your sister you should make an apology to her.A. whomB. for whichC. for

问题补充：

You were rude to your sister, you should make an apology to her.

A. whom

B. for which

C. for whom

D. which

答案：

A. whom

(答案→)B. for which

C. for whom

D. which

解析：考查从句，从句you should make an apology to her不缺少成份，for which相当于why，所以选B