Let $$f:(-\frac{\pi}{2}, \frac{\pi}{2}) \rightarrow R$$ be given by
$$f(x) = (\log (\sec x + \tan x))^3.$$
Then

A

f(x) is an odd function

B

f(x) is a one-one function

C

f(x) is an onto function

D

f(x) is an even function