Which ethyl benzoate is hydrolysed fastest by aqueous NaOH?

The slow step is the attack of $\mathrm{OH}{}^{-}$ on the carbonyl carbon, forming a negatively charged tetrahedral intermediate. The strongly electron-withdrawing $\mathrm{NO}{}_2$ increases the electrophilicity of the carbonyl carbon and stabilises the intermediate, whereas $\mathrm{CH}{}_3$ and $\mathrm{OCH}{}_3$ donate electrons.