If tan \(\theta\) = \(\frac{m^2 - n^2}{2mn}\) find sec\(\theta\)
A
\(\frac{m^2 + n^2}{(m^2 - n^2)}\)
B
\(\frac{m^2 + n^2}{2mn}\)
C
\(\frac{mn}{2(m^2 + n^2)}\)
D
\(\frac{m^2n^2}{2(m^2 - n^2)}\)