Simplify the following expression.

$$\frac{7}{10} \div \frac{3}{7}$$ of $$\left(2\frac{3}{10} + 2\frac{3}{5}\right) + \frac{1}{5} \div 1\frac{2}{5} - \frac{2}{7}$$

A

$$-\frac{4}{21}$$

B

$$\frac{5}{21}$$

C

$$\frac{4}{21}$$

D

$$-\frac{5}{21}$$