Select the option that can replace the question mark (?) in the following equation.

$$ \frac{(0.2)^{2} - (0.1)^{2}}{(0.2 + 0.1)^{2}} $$ = ?

A

$$ \frac{1}{3} $$

B

$$ \frac{3}{40} $$

C

$$ \frac{-7}{90} $$

D

$$ \frac{7}{90} $$