The correct option is D I<III<II
The reactivity of aryl halides towards nucleophilic substitution reactions increases, when one or more electron withdrawing groups such as nitro group are present on the aromatic nucleus.
The reactivity increases with increase in the number of nitro groups.
Also the increase in the reactivity is more when the nitro group is in ortho or para position.
Hence, the correct order for the increasing reactivity with CH3ONa is I<III<II .