Sin 2A = 2 sin A is true when A =

We are given $\sin 2 A=2 \sin A \cdot \cos A$

So

$\Rightarrow \sin 2 A=2 \sin A$

$\Rightarrow 2 \sin A \cdot \cos A=2 \sin A$

$\Rightarrow \cos A=1$

$\Rightarrow \cos A=\cos 0^{\circ}$

As $A=0^{\circ}$

Hence the correct option is (a)