Having studied abroad for many years, he came back to ________ used to be a small town．

1. A.
   where
2. B.
   what
3. C.
   that
4. D.
   which

Having studied abroad for many years, he came back to ______ used to be a small town.

A. where　 　 B. what　 　　　　　C. that　　　　　　　 D. which