—I’m sorry to keep you waiting so long.

—       .

A．I don’t think so                                 B．Don’t say so  

C．It doesn’t matter                                 D．You are right.

—I’m sorry to keep you waiting for me so long.
—_______

---I'm sorry to keep you waiting for me so long．

---________．

1. A.
   I don't think so
2. B.
   Don't say so
3. C.
   It doesn't matter
4. D.
   I'd love to