# Two particles A and B initially at must move towards each other under a mutual force of attraction. The speed of the center of mass at the instant speed of A is V and the speed of B is 2V is

$\begin {array} {1 1} (a)\;v & \quad (b)\;zero \\ (c)\;2v & \quad (d)\;3v \end {array}$

It is a conceptual one