--May I turn on the TV, Mum? I finish my homework.
--- .
A. Yes, please.
B. No, you’d better not.
C. No, you needn’t.
D. Yes, you must.
网友回答
A. Yes, please.
(答案→)B. No, you’d better not.
C. No, you needn’t.
D. Yes, you must.
解析：Yes, please.是的，请吧；No, you’d better not.不，你最好别；No, you needn’t. 不，你不必；Yes, you must. 是的，你必须。根据上文，妈妈，我可以打开电视吗？——我完成了作业。结合语境可知选B，最符合语境。