If $f^{\prime \prime}(x)>0, \forall x \in R, f^{\prime}(3)=0$ and $g(x)=f\left(\tan ^{2} x-2\right.$
$\tan x+4), 0<x<\pi / 2$, then $g(x)$ is increasing in
(A) $\left(0, \frac{\pi}{4}\right)$
(B) $\left(0, \frac{\pi}{4}\right) \cup\left(\frac{\pi}{4}, \frac{\pi}{2}\right)$
(B) $\left(\frac{\pi}{4}, \frac{\pi}{2}\right)$
(D) $\left(0, \frac{\pi}{2}\right)$