Object a with a mass of 500 kilograms hits stationary object b with a mass of 920

Object a with a mass of 500 kilograms hits stationary object b with a mass of 920 kilograms. if the collision is elastic, what happens after the collision?

a)both object a and object b move forward but with different velocities.

b)object a and object b stick together and move forward together.

c)object b moves forward, but object a moves backward.

d)object a stops and object b moves forward.