The expression $$\frac{5-\left[\frac{3}{4}+\left\{2\frac{1}{2}-\left(\frac{1}{2}+\overline{\frac{1}{6}-\frac{1}{7}}\right)\right\}\right]}{6}$$

A

$$\frac{13}{56}$$

B

$$\frac{97}{168}$$

C

$$\frac{191}{504}$$

D

$$\frac{19}{54}$$