If tan 22 $$\frac{1}{2}^\circ$$ =x,then the value of cos 67 $$\frac{1}{2}^\circ$$ is

A

$$\frac{x}{\sqrt{x^{2}+1}}$$

B

$$\frac{1}{\sqrt{x^{2}+1}}$$

C

$$\frac{x}{\sqrt{x^{2}-1}}$$

D

$$\frac{1}{\sqrt{x^{2}-1}}$$