A solid sphere of mass $M$ and radius $R$ spins about an axis passing through its centre making $600 \mathrm{rpm}$. Its kinetic energy of rotation is
(a) $\frac{2}{5} \pi^{2} M R$
(b) $\frac{2}{5} \pi M^{2} R^{2}$
(c) $80 \pi^{2} M R^{2}$
(d) $80 \underline{\pi} R$