We never know( )he is,They say he is a doctor

问题描述:

We never know( )he is,They say he is a doctor
A.whom
B.what
C.where
选哪个~为什么
老师怎么选C的啊

B what's he?他的职业是什么?
后面半句的意思是:他们说他是个医生