With more than 17000 islands, ________ only 6000 are inhabited, Indonesia is the world's largest archipelago(岛国)．

1. A.
   on which
2. B.
   for which
3. C.
   of which
4. D.
   along which

With more than 17000 islands, _____ only 6000 are inhabited, Indonesia is the world’s largest archipelago （岛国）．

       A．on which  B．for which  C．of which   D．along which

 With more than 17000 islands, _____ only 6000 are inhabited, Indonesia is the world’s largest archipelago (岛国).

       A. on which    B. for which   C. of which    D. along which

 With more than 17000 islands, ______ only 6000 are inhabited, Indonesia is the world’s largest archipelago(岛国).

A. on which           B. for which                C. of which                 D. along which