A spring is compressed between two objects with unequal masses, m and M, ad held together. The objects are initially at rest on a horizontal frictionless surface. When released, which of the following is true?

The complete question is here.

A spring is compressed between two objects with unequal masses, m and M, held together. The objects are initially at rest on a horizontal friction less surface. When released, which of the following is true?

a) Kinetic energy is same as before being released

b) The total final kinetic energy is zero.

c) The two objects have equal kinetic energy.

d) The speed of one object is equal to the speed of other.

e) The total final momentum of two objects is zero.

So option e) the total final momentum of two objects is zero.