You _____________return the book now. You can keep it till next

You _____________return the book now. You can keep it till next week if you like.
A、can’t
B、mustn’t
C、needn’t
D、may not
【正确答案】：C
【题目解析】：needn’t没有必要；can't(不能)，mustn't(不准)，may not(不可以)，均不合题意。