Answer is B.
Here's the partial explanation:
"Statement (2) alone is sufficient since division by the number 4 must terminate: the remainder when dividing by 4 must be 0, 1, 2, or 3, so the quotient must end with .0, .25, .5, or .75, respectively."
Is this true for r/s if s = any integer?
For instance, I tried the case when s = 5. The remainders are 0, 1, 2, 3, or 4. The quotient terminates in all cases.
Another way of looking at it is: Can anyone give an example of a similar question where the decimal doesn't terminate?
It would always be true with 5, as in the example above. Also 2, 8, 1, and 10. But it wouldn't work with 3, 6, or 9, and perhaps not 7 either. There are different patterns for different numbers, and it pays to be comfortable with all of them.
That said, I think it's a good question.