参考答案：D

解析：

It is probably easiest to determine the values of △ and by plugging in values, which is ugly, but there are ways to simplify your computations. If you look at the answer choices, you will see that 8 and 7 are not factors of any of the choices, so you do not need to try them. Also, if you examine possible values for , you might realize that has to be greater than 2 because 200×200=40,000, which is much less than 80,698, so  is probably 3 or 4, since 200×300=60,000 and 200×400=80,000. Neither 3 nor 4 is a factor of answer B, 10, so you can eliminate that answer. Plug in the corresponding values of the other answer choices for and A:A:(3,2); C:(3,4) and (4,3); and D:(3,5); you will find that D, 15, is the only answer with factors that will make the computation work properly, so D is the answer.