If $$2x-y = 2$$ and $$xy=\frac{3}{2}$$, then what is the value of $$x^{3}-\frac{y^{3}}{8}$$?

A

$$\frac{9}{2}$$

B

$$-\frac{5}{4}$$

C

$$\frac{5}{2}$$

D

$$\frac{13}{4}$$