Answer: D

While factorials can be time-consuming to calculate, we don't need to find the exact answer on a Data Sufficiency question. In this case, it is sufficient to know that we could solve. To do so, all we would need is the value of x.

Statement (1) is sufficient. Given one variable, as we are here, we can determine which value of x - 1 has a factorial equivalent to 720. (It turns out that if x = 7, x - 1 = 6, and 6! = 720.)

Statement (2) is also sufficient. We can determine from the statement that x = 7. (Remember, x must be positive.) That's enough to answer the question. Choice (D) is sufficient.

One more note. On more advanced questions, it might be handy to recognize that (x + 1)! = (x + 1)(x)(x - 1)!, so when it is divided by (x - 1)!, the result is (x + 1)(x)--statement (2). If you needed to solve for (x + 1)! divided by (x - 1)!, that would be a simple way of reaching a solution.