If $$\Box$$ is defined by $$a \Box b = \frac{a - b}{a + b}$$, $$\diamondsuit$$ by $$a \diamondsuit b = \frac{a + b}{a - b}$$, $$rightarrow$$ is defined by $$a \rightarrow b = ab$$, then $$\frac{(55 \Box 5) \rightarrow (77 \diamondsuit 7)}{(2 \Box 3)\rightarrow(4 \diamondsuit 5)} =$$

A

$$\frac{-5}{9}$$

B

1

C

$$\frac{9}{5}$$

D

$$\frac{5}{9}$$