The value of $$\cos^{2}\frac{\pi}{8} + \cos^{2}\frac{3\pi}{8} + \cos^{2}\frac{5\pi}{8} + \cos^{2}\frac{7\pi}{8} + $$ is

A

1

B

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

C

2

D

$$\frac{9}{4}$$