— Margaret ________ stay at home all day long in front of the computer.

— That's right. She should go to the fitness center with us. [    ]

A. doesn't have to  

B. couldn't

C. oughtn't to  

D. may not

车主服务中，一个手机号码可以利用点播方式查询（）车牌号码的违法信息，但一次只能查（），不能同时查（）。