Evaluate : $\sin 18^{\large\circ}$

Question

$\begin{array}{1 1}(A)\;\large\frac{\sqrt 5-1}{4}\\(B)\;\large\frac{\sqrt 5+1}{4}\\(C)\;\large\frac{\sqrt 7-1}{4}\\(D)\;\large\frac{\sqrt 7+1}{4}\end{array}$