The intermediate formed in aromatic nucleophilic substitution reaction is carbanion. Carbanion stabilised by electron withdrawing groups. Aryl halides are less reactive towards nucleophilic aromatic substitution with aqueous NaOH. Introduction of electron releasing group like OCH3 group further decreases its reactivity towards nucleophilic substitution. But the introduction of electron withdrawing groups like NO2 group particularly at the ortho and para position increases its reactivity towards nucleophilic substitution. Higher the number of electron withdrawing groups, higher the reactivity.
∴ The correct reactivity order is

