If $$\cos^2 \theta - \sin^2 \theta - 3 \cos \theta + 2 = 0, 0^\circ < \theta < 90^\circ$$, then what will be the value of $$\sec \theta - \cos \theta$$?

A

$$\frac{4}{3}$$

B

$$\frac{1}{2}$$

C

$$\frac{3}{2}$$

D

$$\frac{2}{3}$$