I don’t doubt_______ he took the first place in his class; but I do doubt_______ he will succeed in the end.

I don’t doubt_______ he took the first place in his class; but I do doubt_______ he will succeed in the end.

1. A.
   if; that
2. B.
   but; which
3. C.
   whether; whether
4. D.
   that; whether

I don’t doubt_______ he took the first place in his class; but I do doubt_______ he will succeed in the end.

       A .if; that       B. but; which  C. whether; whether      D. that; whether

I don’t doubt_______ he took the first place in his class; but I do doubt_______ he will succeed in the end.