Identify the correct order of increasing ionic sizes

The electronic configurations of the given ions are

${\mathrm{Al}}^{3+}:\left(1s{)}^2\right(2s{)}^2(2p{)}^6{\mathrm{F}}^{-}:(1s{)}^2\left(2s{)}^2\right(2p{)}^6$

${\mathrm{O}}^{2-}:\left(1\mathrm{s}{)}^2\right(2\mathrm{s}{)}^2(2\mathrm{p}{)}^6 {\mathrm{Cl}}^{-}:(1s{)}^2\left(2s{)}^2\right(2p{)}^6\left(3s{)}^2\right(3p{)}^6$

The size of ${\mathrm{Cl}}^{-}$ will be the largest as its outer shell belongs to the quantum number n = 3. Of the remaining species,

${\mathrm{Al}}^{3+}$ will have the minimum ionic size because of three positive charge and $\mathrm{O}{2}^{-}$will have maximum ionic size because of two negative charge.