In the figure $AP$ is a tangent to the circle with centre $O$ such that $OP= 4\;cm$ and $\angle {OPA} = 30^{\circ}$. Then AP

Question

$\begin{array}{1 1}(a)\; 2 \sqrt 2 cm \\(b)\; 2\;cm \\(c)\; 2\sqrt 3 \\ (d)\; 3 \sqrt 2 \end{array}$