ANSWER
The correct answer is option C
EXPLANATION
The graph of [tex]f(x)=tan^{-1}(x)[/tex] is shown in the attachment.
You can see clearly that as
[tex]x\rightarrow \infty, f(x)\rightarrow \frac{\pi}{2}[/tex]
and as
[tex]x\rightarrow -\infty, f(x)\rightarrow -\frac{\pi}{2}[/tex]
These are are actually the two horizontal asymptotes to the given function.
