Answer: Choice A; (x+2)(x-2)
We can factor x^2-4 into (x+2)(x-2) using the difference of squares rule. Notice how (x+2) is a factor, and its found in the other denominator as well. The missing term in the second denominator is (x-2). If we multiply top and bottom of the second fraction by (x-2), then we'll get to the LCD