Explanation

We are asked for . There is not a ton of simplifying that we can do with the expression, although the a terms can be combined to give:



Although the numerator and denominator here look similar, there is not a common factor between them that can be cancelled out. On to the data statements, separately first.

Statement (1) gives us an equation with a and b. This is the only equation we have at this point, so we will be able to solve for the expression that we are looking for only through fortuitous algebra. We can cross-multiply:









If we substitute this conclusion from the statement into our expression of interest, we get:



Now, all the terms have one b, so it can be factored out and canceled as . That means that we will determine a unique value for the expression. So Statement (1), it turns out, is sufficient.

Statement (2), like Statement (1), gives us a single equation, and in this case, there is no fortuitous algebra. We can eliminate the variables from the bottom of our expression of interest, but there's nothing we can do with the top of the fraction, since we can't solve for a and b individually and there's no way to factor out a-b in the numerator. Insufficient.

The correct answer is (A).