A thin uniform rod of length L and mass M is bent into a circular hoop. Which one of the following describes the rotational inertia of this hoop about an axis through its rim, perpendicular to the plane of the hoop?
A. ML^2
B. ML^2/3pi^2
C. ML^2/pi^2
D. ML^2/2pi^2
E. ML^2/4pi^2