Shown in the figure is a hollow ice-cream cone (it is open at top). If its mass is M, radius of its top is R and height, H, then its moment of inertia about its axis is:

A

$$\frac{MR^2}{2}$$

B

$$\frac{M(R^2+H^2)}{4}$$

C

$$\frac{MH^2}{3}$$

D

$$\frac{MR^2}{3}$$