It was in the mid-1980s that cartoons began to take off in China,_________there were only pictured-story books.

A.when                        B.after that                   C.before which             D.where

It was in the mid-1980s that cartoons began to take off in China,_________there were only pictured-story books.

1. A.
   when
2. B.
   after that
3. C.
   before which
4. D.
   where