Find two numbers that multiply to -28 (last term) and add to -3 (middle term)
Those two values are -7 and 4
-7 plus 4 = -3
-7 times 4 = -28
Since the numbers are -7 and 4, this means the given expression factors to (x-7)(x+4)
The two factors are x-7 and x+4
The factor x+4 isn't listed in the list of answer choices, so we can ignore it. The factor x-7 is listed as choice B, so that is the only answer.