A particle of mass `M` and charge `Q` moving with velocity `vec(v)` describe a circular path of radius `R` when subjected to a uniform transverse magnetic field of induction `B`. The work done by the field when the particle completes one full circle is
A. `(BQv)(2pi R)`
B. `((Mv^(2))/(R ))2pi R`
C. zero
D. `(BQ) (2pi R)`
