Option B is the correct answer.

Velocity has the unit $\rm ms^{-1}$.

We know, $\rm velocity = \frac{displacement}{time taken}$

The fundamental unit of displacement is ‘m’ and that of time is ‘s’.

Thus, the unit of velocity is $\rm \frac{m}{s} = ms^{-1}$.

On the other hand, the units of acceleration, force, and density are $\rm ms^{-2}$, $\rm kgms^{-2}$, and $\rm kgm^{-3}$, respectively.