If $$\sin (A - B) = \frac{1}{2}$$ and $$\cos (A + B) = \frac{1}{2}$$, then what is the value of $$\sin A \cos A + \sin^2 A \sin B \cos B + \cos^3 A \cos B \tan A$$?

A

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

B

$$\frac{3}{4}$$

C

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

D

$$\frac{3}{2}$$