If $$\frac{a}{b}$$ is a fraction, where $$a = b - 3$$ and $$\frac{(a + 10)}{b} - \frac{a}{b} = \frac{10}{7}$$, then find $$\frac{a}{b}$$.

A

$$\frac{4}{7}$$

B

$$\frac{5}{8}$$

C

$$\frac{8}{11}$$

D

$$\frac{2}{5}$$