A 300-G Billiard Ball Travelling at 2 M/s Collides Elastically

Multiple Choice

A 300-g billiard ball travelling at 2 m/s collides elastically with an identical stationary billiard ball and bounces off at a 30 degree angle.What is the angle of the other ball's path with respect to the path of the original ball?

A) 15 degrees
B) 17 degrees
C) 22.5 degrees
D) 60 degrees
E) More information is needed.