A Billiard Ball Is Moving in the X Direction at 40.0

Multiple Choice

A billiard ball is moving in the x direction at 40.0 cm/s and strikes another billiard ball moving in the y direction at 30.0 cm/s.As a result of the collision,the first ball moves at 50.0 cm/s,and the second ball stops.What is the change in kinetic energy of the system as a result of the collision?

A) 0
B) some positive value
C) some negative value
D) No answer above is correct.