If $$a \neq b$$ and $$ab \neq 0$$ then $$\left\{\frac{(ab)^{\frac{1}{4}} - b^{\frac{1}{2}}}{a^{\frac{1}{2}} - (ab)^{\frac{1}{4}}}\right\}^{-4} = $$

A

$$\frac{b}{a}$$

B

$$\frac{a}{b}$$

C

$$-\frac{b}{a}$$

D

$$-\frac{a}{b}$$