In an Elastic Collision of Two Objects

Multiple Choice

In an elastic collision of two objects,

A) momentum is not conserved.
B) momentum is conserved,and the kinetic energy after the collision is less than its value before the collision.
C) momentum is conserved,and the kinetic energy after the collision is the same as the kinetic energy before the collision.
D) momentum is not conserved,and the kinetic energy of the system after the collision differs from the kinetic energy of the system before the collision.
E) the kinetic energy of the system after the collision depends on the masses of the objects.