A Charged Particle of Mass 0

Multiple Choice

A charged particle of mass 0.0040 kg is subjected to a 4.0-T magnetic field which acts at a right angle to its motion. If the particle moves in a circle of radius 0.10 m at a speed of 2.0 m/s, what is
The magnitude of the charge on the particle?

A) 0.00040 C
B) 2500 C
C) 0.020 C
D) 50 C