I knew the boy( )you talked about yesterdayI knew the boy( )you talked about yesterdayA.which B.who C.whom D.whose想问一下为什么选C不选B呢?

I knew the boy( )you talked about yesterdayI knew the boy( )you talked about yesterdayA.which B.who C.whom D.whose想问一下为什么选C不选B呢?
I knew the boy( )you talked about yesterday
I knew the boy( )you talked about yesterday
A.which B.who C.whom D.whose
想问一下为什么选C不选B呢?

I knew the boy( )you talked about yesterdayI knew the boy( )you talked about yesterdayA.which B.who C.whom D.whose想问一下为什么选C不选B呢?
这是个定语从句,whom是宾语,who是主语,原题中talked about 后接句子成分为宾语,所以用whom.希望有用

如果选C 的话，about要放到whom前面