Was it in the factory ________ we used to work ________ the accident occurred?

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

Was it in the factory ______ we used to work _____ the accident occurred ?

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