A Hockey Puck with a Mass of 160 G Slides

Multiple Choice

A hockey puck with a mass of 160 g slides at a speed of 12 m/s on frictionless ice.The puck runs into a small box with a mass of 850 g that is initially at rest.Assuming that the collision is elastic,what is the speed of the box after the collision?

A) 2.3 m/s
B) 3.8 m/s
C) 5.6 m/s
D) 6.0 m/s
E) 8.2 m/s