Did you hear the loud noise _____ the flash of light last ni

Did you hear the loud noise _____ the flash of light last night? Yes,I ____ TV. A.followin
Did you hear the loud noise _____ the flash of light last night?
Yes,I ____ TV.
A.following,watched
B.following,was watching
C.followed,had watched
D.followed.was watching
为什么following