The decreasing order of reactivity of $\mathrm{m}$-nitrobromo benzene ($\mathrm{I}$); $2,4,6$-trinitrobromobenzene ($\mathrm{II}$); $\mathrm{p}$-nitro bromobenzene ($\mathrm{III}$); and $2,4$ dinitrobromobenzene ($\mathrm{IV}$) towards ${\mathrm{OH}}^{-}$ ions is: