If $\frac{1}{1^2}+\frac{1}{2^2}+\frac{1}{3^2}+$......upto $\infty$ = $\frac{\phi^2}{g}$, then $\frac{1}{1^2}+\frac{1}{3^2}+\frac{1}{5^2}+$.....upto $\infty$ will be

Question

$(a)\;\frac{\phi^2}{9}\qquad(b)\;\frac{\phi^2}{6}\qquad(c)\;\frac{\phi^2}{12}\qquad(d)\;\frac{\phi^2}{18}$