If $\sec\theta=m$ and $\tan\theta=n$ then $\large\frac{1}{m}$$\big[(m+n)+\large\frac{1}{(m+n)}\big]$

Question

$\begin{array}{1 1}(a)\;2&(b)\;2m\\(c)\;2n&(d)\;mn\end{array}$