A loaded spring gun of mass M fires a bullet of mass m with a velocity v at an angle of elevation `theta`. The gun is initially at rest on a horizontal smooth surface. After firing, the centre of mass of the gun and bullet system
A. Moves with a velocity v `m//M`
B. Moves with velocity `(vm)/(M)` cos 0 in the horizontal direction
C. Remains at rest
D. Moves with a velocity `("vmsin0")/(M)` in the vertical direction
