-Are you going to the lecture tomorrow afternoon ?

-I’m not sure now . I _______ go to Prof . Black’s class instead .

A．might              B．would              C．should                    D．must

-Are you going to the lecture tomorrow afternoon?

-I'm not sure now．I ________ go to Prof．Black's class instead．

1. A.
   might
2. B.
   would
3. C.
   should
4. D.
   must