If $A+B+C=\pi$ then $\sin 2A+\sin 2B+\sin 2C$ is equal to

Question

$\begin{array}{1 1}(a)\;4\sin A\sin B\sin C&(b)\;\sin A\sin B\sin C\\(c)\;2\sin A\sin B\sin C&(d)\;None\;of\;these\end{array}$