The value of $$\frac{(p - q)^{3} + (q - r)^{3} + (r - p)^{3}}{12(p - q)(q - r)(r - p)}$$, where $$p \neq q \neq r$$, is equal to:$$

A

$$\frac{1}{9}$$

B

$$\frac{1}{3}$$

C

$$\frac{1}{4}$$

D

$$\frac{1}{2}$$