(c)
The given function is defined when $x^{2} - 1;3 + x > 0$ and $3 + x \neq 1$
$\Rightarrow \ \ \ \ x^{2} > 1;\ \ \ 3 + x > 0$ and $x \neq - 2$
$\Rightarrow \ \ \ \ - 1 > x > 1;\ \ x > - 3$, $\ x \neq - 2$
$\therefore$ Domain of the function is
$D_{f} = ( - 3,\ - 2) \cup ( - 2,\ - 1) \cup (1,\ \infty)$