The $\mathrm{As}$-$\mathrm{Cl}$ bond distance in ${\mathrm{AsCl}}_3$ is $2.20 \mathrm{A}$. Estimate the covalent radius of $\mathrm{As}$.

Select the correct statement(s).

($\mathrm{I}$) Polarizability of ${\mathrm{S}}^{2-}$ is lower than ${\mathrm{Se}}^{2-}$
($\mathrm{II}$) Polarizability of ${\mathrm{S}}^{2-}$ is higher than ${\mathrm{Cl}}^{-}$
($\mathrm{III}$) Polarizability of ${\mathrm{S}}^{2-}$ is lower than ${\mathrm{P}}^{3-}$
($\mathrm{IV}$) Polarizability of ${\mathrm{O}}^{2-}$ is higher than ${\mathrm{S}}^{2-}$