If $$y(\theta) = \frac{2\cos\theta + \cos 2\theta}{\cos 3\theta + 4\cos 2\theta + 5\cos\theta + 2}$$, then at $$\theta = \frac{\pi}{2}$$, $$y'' + y' + y$$ is equal to :

A

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

B

1

C

2

D

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