If $$x^2 + (4 - \sqrt{3})x - 1 = 0$$, then what is the value of $$x^2 + \frac{1}{x^2}?$$

A

$$9 - 8\sqrt{3}$$

B

$$21 - 12\sqrt{3}$$

C

$$21 - 8\sqrt{3}$$

D

$$17 - 8\sqrt{3}$$