Particles of mass $2 M, m$ and $M$ are, respectively, at point $\mathrm{A}, \mathrm{B}$ and $\mathrm{C}$ with $A B=\frac{1}{2}(B C) \cdot m$ is very much smaller than $M$ and at time $t=0$, they are all at rest as given in Fig. 7.10. At subsequent times before any collision takes place.
(A) $m$ will remain at rest.
(B) $m$ will move towards $M$.
(C) $m$ will move towards $2 M$.
(D) $m$ will have oscillatory motion.