The correct option is D III>I>II>IV
The presence of −R,−I,−H groups decrease the reactivity of benzene towards aromatic electrophilic substitution reaction.
−CF3 group is a strong −I group and it decreases the reactivity of benzene towards electrophilic aromatic substitution reaction.
The presence of +R,+I,+H groups increase the reactivity of the benzene towards aromatic electrophilic substitution reaction.
−CH3 shows hyperconjugation and is +I group whereas −OCH3 is +R group.
+R effect dominates over +H effect, hence the order will be: III>I>II>IV