If $$\cos \theta = \frac{4x}{1 + 4x^2}$$, then what is the value of $$\sin \theta$$?s

A

$$\frac{1 + 4x^2}{1 - 4x^2}$$

B

$$\frac{1 + 4x^2}{4x^2}$$

C

$$\frac{1 - 4x^2}{1 + 4x^2}$$

D

$$\frac{1 - 4x^2}{4x}$$