If $$4 - 2 \sin^2 \theta - 5 \cos \theta = 0, 0^\circ < \theta < 90^\circ$$, then the value of $$\cos \theta - \tan \theta$$ is:

A

$$\frac{1 + 2 \sqrt 3}{2}$$

B

$$\frac{2 - \sqrt 3}{2}$$

C

$$\frac{2 + \sqrt 3}{2}$$

D

$$\frac{1 - 2 \sqrt 3}{2}$$