proportional to both the magnitude of the charge and the velocity v
independent of the magnitude of the charge
proportional to the velocity v only
proportional to the magnitude of the charge only
Correct answer is A
The magnetic force on a charge is given by
F = qVB Sinθ,
thus the force is proportional to both the magnitude by the charge (q) and the velocity (V)
(i/e F α qV)