$\int \limits _0^{\omega} \large\frac{x^2}{(x^2+a^2) (x^2+b^2) (x^2+c^2)}$$dx= \large\frac{\pi}{2(a+b)(b+c)(c+a)}$ then find $\int \limits _0^{\omega} \large\frac{dx}{(x^2+4)(x^2+g)}$

Question

\[\begin {array} {1 1} (a)\;\frac{\pi}{20} \\ (b)\;\frac{\pi}{40} \\ (c)\;\frac{\pi}{60} \\ (d)\;\frac{z}{80} \end {array}\]