____ puzzled the mother most was ____the son would never agree with her.

A．What; why

B．That; how

C．Which; when

D．What; where

下列各项中，属于注册会计师及其所在的会计师事务所的承办会计咨询、服务业务范围的有（）。

A.培训会计人员

B.担任会计顾问

C.代办申请注册登记

D.代理纳税申报