Adam is right the answer is B. The reason is because although they might have the same Force, they wont have the same acceleration. Why?
Because Force = Mass * Acceleration
and we all know that if they have equal Forces and different masses (a gun has more mass than a bullet) there accelerations will be different. In this case the gun has alot more mass than the bullet so its acceleration will be much smaller to produce the same force. On the opposite side the bullet has alot less mass and to make up for that accelerates at a much higher number than the gun (which is why bullets go so fast =P).
That was easy Nodice…College Physics is tedious but not that hard =P