I don't doubt ________ he'll come.  

I don't doubt ________ he'll come.

1. A.
   that
2. B.
   if
3. C.
   what
4. D.
   whether

I don't doubt ________ he'll come.  

A. that       B. if                  C. what            D. whether

I don't doubt ________ he'll come.

A. that

B. if

C. what

D. whether

I don't doubt ________ he'll come.