A Basketball with a Mass of 0

Multiple Choice

A basketball with a mass of 0.5 kg is bounced on the floor.Right before impact,it has a speed of 10 m/s,and right after it has 8 m/s.What is the impulse of the collision,and of which type is the collision?

A) 1 Ns,elastic
B) 5 Ns,elastic
C) 9 Ns,elastic
D) 1 Ns inelastic
E) 9 Ns,inelastic