A smooth sphere A is moving on a frictionless horizontal plane with angular speed `omega` and centre of mass velocity `upsilon`. It collides elastically and head on with an identical sphere B at rest. Neglect friction everywhere. After the collision, their angular speeds are `omega_A and omega_B` respectively. Then
A. `w_(A) lt w_(B)`
B. `w_(A) = w_(B)`
C. `w_(A) = w`
D. `w_(B) = 0`
