By D it has three digits

The third digit can't be more than 2 because by B, any larger digit multiplied
by 4 is too big to be a single digit.  It can't be 0 because by B, that would
make the first digit 0, which it can't be, and so the third digit is either
1 or 2.

If the third digit were 1, then by B the first digit would be 4, and by C, the
second digit would be 3, making the number 431, but A rules that out because
4+3+1 is not 16.

So the third digit must be 2, and by B the first digit must be 8, and by C, the
second digit would be 6, making the number 862, and that satisfies A because
8+6+2 = 16.    

So the answer is 862.

Edwin