--May I play computer games, Mum?
--Sorry, you _________. You have to put your heart into your exams.
A. may not B. needn't C. can't D. don't have to
--May I play computer games, Mum?
--Sorry, you _________. You have to put your heart into your exams.
A. may not B. needn't C. can't D. don't have to
C