Consider a system of two particles having masses $m_1$ and $m_2$ . If the particle of mass $m_1$ is pushed towards the mass centre of particles through a distance 'd', by what distance would the particle of mass $m_2$ move so as to keep the mass centre of particles at the original position

Question

( A ) $\frac {m_2}{m_1}$
( B ) $d$
( C ) $\frac {m_1}{m_1+m_2}d$
( D ) $\frac {m_1}{m_2}d$