If $f(x)=\frac{x(\sin x+\tan x)}{\left[\frac{x+\pi}{\pi}\right]-\frac{1}{2}}$, where $[$ ] denotes greatest
integer function, then
(A) $f(x)$ is an odd function if $x=n \pi$
(B) $f(x)$ is an even function if $x \neq n \pi$
(C) $f(x)$ is an odd function if $x \neq n \pi$
(D) $f(x)$ is an even function if $x=n \pi$