A charged particle of mass $$m$$ and charge $$q$$ travels on a circular path of radius $$r$$ that is perpendicular to a magnetic field $$B$$. The time taken by the particle to complete one revolution is

A

$$\frac{2\pi mq}{B}$$

B

$$\frac{2\pi q^2 B}{m}$$

C

$$\frac{2\pi q B}{m}$$

D

$$\frac{2\pi m}{q B}$$