A Bullet with a Mass of 20 G and a Speed

Multiple Choice

A bullet with a mass of 20 g and a speed of 960 m/s strikes a block of wood of mass 4.5 kg resting on a horizontal surface.The bullet gets embedded in the block.The speed of the block immediately after the collision

A) cannot be found because we don't know whether the surface is frictionless.
B) is 0.21 km/s.
C) is 65 m/s.
D) is 9.3 m/s.
E) None of these is correct.