Subject :NSO Class : Class 9

A large spherical mass M is fixed at one position and two identical point masses m are kept on a line passing through the centre of M (see figure). The point masses are connected by a rigid massless rod of length l and this assembly is free to move along the line connecting them. All three masses interact only through their mutual gravitational interaction. When the point mass nearer to M is at a distance
r = 3l from M and tension in the rod is zero then the acceleration of point mass will be

AGM/9l^{2}

BGM/16l^{2}

C25/288 GM/l_{2}

D7/144 GM/l_{2}

There is only answer..... No explanation.....PLS help