Solve for x:
$$\sin^2 x - 4 \sin x + 3 = 0, 0 \leq x \leq \frac{\pi}{2}$$

A

$$\frac{\pi}{2}$$

B

$$\frac{\pi}{4}$$

C

$$\frac{\pi}{6}$$

D

$$\frac{\pi}{3}$$