Answer the question based on the information given below:
Let x and y be real numbers and let
$f(x, y) = |x+y|, F(f(x, y)) = -f(x,y) \text{ and } G(f(x, y)) = -F(f(x, y))$
Which of the following expressions yields $x^2$ as a result?
- $F(f(x, -x)).G(f(x, -x))$
- $F(f(x, x)).G(f(x, x)).4$
- $-F(f(x, x)).G(f(x, -x)) \: \log_2 16$
- $f(x,x).f(x,x)$