It's said that the conference to be held in Room 223 ________ till next Friday．

1. A.
   will put off
2. B.
   was put off
3. C.
   has been put off
4. D.
   is putting off

It's said that the conference to be held in Room 223 ____ till next Friday.

　　 A. will put off　 B. was put off　 C. has been put off　 D. is putting off