If $$x$$ is so small that $$x^3$$ and higher powers of $$x$$ may be neglected, then $$\frac{(1 + x)^{3/2} - \left(1 + \frac{1}{2} x\right)^3}{(1 - x)^{1/2}}$$

A

$$1 - \frac{3}{8} x^2$$

B

$$3x + \frac{3}{8} x^2$$

C

$$-\frac{3}{8} x^2$$

D

$$\frac{x}{2} - \frac{3}{8} x^2$$