In the given figure, $$ABC$$ is an isosceles triangle with $$BC = 8 cm$$ and $$AB = AC = 5 cm$$. The value of $$\tan C - \cot B$$ is

A

$$-\frac{5}{12}$$

B

$$-\frac{7}{12}$$

C

$$\frac{7}{12}$$

D

$$\frac{5}{12}$$