If $mx^m - nx^n= 0$, then what is the value of $\frac{1}{x^m+x^n}+\frac{1}{x^m-x^n}$ terms of $x^n$ is: Where x, m, n are > 0

$2mn/(x^n (n^2 + m^2)$ $2mn/(x^n (m^2 - n^2)$ $2mn/(x^n (m^2 + n^2)$ $2mn/(x^n (n^2 - m^2)$

$2mn/(x^n (n^2 - m^2)$