Find the equation of a diameter bisecting a system of parallel chords of slope m of the hyperbola $\large\frac{x^2}{a^2}-\frac{y^2}{b^2}$$=1$?

Question

$\begin{array}{1 1}(a)\;y=\large\frac{b^2x}{a^2m}\\(b)\;y=\large\frac{a^2x}{b^2m}\\(c)\;y=\large\frac{bx}{am}\\(d)\;\text{None of these}\end{array}$