If the function $$f(x)=\frac{e^{x}(e^{\tan x-x}-1)+\log_{e}{(\sec  x+\tan x)}-x}{\tan x-x}$$ is continuous at x = 0, then the value of f(O) is equal to

A

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

B

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

C

2

D

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