She thought I was talking about her son,___ in fact,I was talking about my son.

问题描述:

She thought I was talking about her son,___ in fact,I was talking about my son.
A.whom B.where C.which D.while
请说明理由.

选D
表示转折和对比.
她以为我在谈论她儿子,但是实际上,我说的是我儿子.