An object of mass m moves in a horizontal circle of radius r with a constant speed v. What is the rate at which work is done by the centripetal force?

A.     \(\frac{{m{v^3}}}{r}\)

B.     \(\frac{{m{v^3}}}{{2\pi r}}\)

C.     \(\frac{{m{v^3}}}{{4\pi r}}\)

D.     zero

D