The Figure Shows Two Boxes,with M₁ > M₂,that Are on a Level

Multiple Choice

The figure shows two boxes,with m₁ > m₂,that are on a level frictionless surface.We can exert a horizontal force $\overrightarrow { \mathrm { F } }$ either toward the right on m₁ or toward the left on m₂.The magnitude of the force that the boxes exert on each other is

A) zero newtons in either case.
B) larger if $\overrightarrow { \mathrm { F } }$ is applied toward the right.
C) larger if $\overrightarrow { \mathrm { F } }$ is applied toward the left.
D) the same in either case.