Question

---Must I clean the floor now?

---__________. It is too dirty.

1. A.
   Yes, you needn’t
2. B.
   No, you needn’t
3. C.
   No, you mustn’t
4. D.
   Yes, you must

Answer 1

D
对于must 引导一般疑问句的肯定回答为yes ，….must否定回答为no，….needn’t/don’t have to，故选D