A 11.5 kg rifle fires a 0.05 kg bullet with a muzzle velocity of 600 m/s. What is the magnitude of the momentum of the rifle due to recoil after the gun has been fired?
a. 3.45 kg m/s
b. 3450 kg m/s
c. 0.0345 kg m/s
d. 0.00345 kg m/s