i am sure you would rather she went to school by bus,___?

i am sure you would rather she went to school by bus,___?
A.hadn't you B.wouldn't you C.aren't D.didn't she
我任为选B,但答案好象是D.
我认为：i am sure
you would rather
she went to school by bus 分3部分,i am sure 主语是I ,不对自身反问,you would rather可接反问故用wouldn't you ．而she went to school by bus 只作宾语从句的宾语