Answer:
Option B
Explanation:
When a charged particle moves in a constant magnetic field it experiences a force in a direction perpendicular to its motion, therefore changing the direction of motion of particle where the speed of the particle remains same.
Since the force is in perpendicular direction to the direction of motion of the particle, there is no work done by the magnetic field on the charged particle.
Therefore, when a charge particle moves through a constant magnetic field, no work is done by the magnetic field on the charge particle.