Chọn khẳng định đúng 1/(x^2 + 4x + 4) - 1/(x^2 - 4x + 4)

A. $(\frac{1}{x^2+4x+4}-\frac{1}{x^2-4x+4}):(\frac{1}{x+2}+\frac{1}{x-2})=\frac{-4}{x^2-4}$

B. $(\frac{1}{x^2+4x+4}-\frac{1}{x^2-4x+4}):(\frac{1}{x+2}+\frac{1}{x-2})=\frac{4}{x^2-4}$

C. $(\frac{1}{x^2+4x+4}-\frac{1}{x^2-4x+4}):(\frac{1}{x+2}+\frac{1}{x-2})=\frac{8}{x^2-4}$

D. $(\frac{1}{x^2+4x+4}-\frac{1}{x^2-4x+4}):(\frac{1}{x+2}+\frac{1}{x-2})=\frac{-8}{x^2-4}$