A long horizontal rod has a bead which can slide along its length and initially placed at a
distance L from one end A of the rod. The rod is set in angular motion about A with constant angular acceleration `alpha.` if the coefficient of friction between the rod and the bead is `mu`, and gravity is neglected, then the time after which the bead starts slipping is

Options

A. `sqrt(mu//a`
B. `mu//sqrt a`
C. `1//sqrt(mu alpha`
D. infinitesemial