# A hoop of radius r and mass m rotating with an angular velocity $\omega_0$ is placed on a rough horizontal surface. The initial velocity of the centre of the hoop is zero. What will be the velocity of the centre of the hoop when it ceases to slip?
( A ) $\frac{r \omega_0}{2}$
( B ) $\frac{r \omega_0}{4}$
( C ) $r \omega_0$
( D ) $\frac{r \omega_0}{3}$