Two Cars Approach Each Other and Collide Head-On

Multiple Choice

Two cars approach each other and collide head-on.Car 1 has a mass of 800 kg and a velocity of -20 m/s.Car 2 has a mass of 1000 kg and a velocity of +16 m/s.They have an inelastic collision,but don't stick to each other.After the collision,car 1 has a velocity of 5 m/s.What is the fraction of kinetic energy lost?

A) 94%
B) 89%
C) 50%
D) 37%
E) 18%