--Mr.john,we must hand in our homework today,_______?

--Mr.john,we must hand in our homework today,_______?
--No ,you ______.But you must bring it to school tomorrow.
A needn't we ;mustn't B mustn't we needn't
C mustn't you mustn't D needn't we need't
但是这个题,第一个空,是反意疑问句,must的反意疑问句应该是needn't呀,请大家说明理由