A stationary particle explodes into two particles of masses $m_1$ and $m_2$ which move in opposite directions with velocities $v_1$ and $v_2$. The ratio of their kinetic energies $\frac{E_1}{E_2}$ is :

Question

( A ) $\frac{m_1}{m_2}$
( B ) $\frac{m_1v_2}{m_2 v_1}$
( C ) 1
( D ) $\frac{m_2}{m_1}$