If a sphere of mass `m` moving with velocity `u` collides with another identical sphere at rest on a frictionless surface, then which of the following is correct ?

Options

A. Angle between their final velocities may be `90^(@)`
B. Loss of kinetic energy due to their collision lies between `0` to `(1)/(4)mu^(2)`
C. Colliding sphere may return back
D. There is a possibility of final kinetic energy being more than `(1)/(2)mu^(2)`