Find the general solution of the equation $5\cos^2\theta+7\sin^2\theta-6=0$

Question

$\begin{array}{1 1}(A)\;n\pi\pm \large\frac{\pi}{4}&(B)\;n\pi\pm \large\frac{\pi}{6}\\(C)\;n\pi\pm \large\frac{\pi}{8}&(D)\;2n\pi\pm \large\frac{3\pi}{4}\end{array} $