The value of $\cos 12^{\large\circ}+\cos 84^{\large\circ}+\cos 156^{\large\circ}+\cos 132^{\large\circ}$ is

Question

$\begin{array}{1 1}(A)\;\large\frac{1}{2}&(B)\;1\\(C)\;\large\frac{-1}{2}&(D)\;\large\frac{1}{8}\end{array} $