I'm wondering why Mr. Smith hasn't              _yet.    [ ]

A. took on                    

B. turned on    

C. took up                    

D. turned up

根据《商业银行、信用社代理支库业务审批工作规程》，对申请人提交的代理支库业务的申请材料存在错误可以当场更正的，初审行应当允许申请人当场更正。