Identify the correct order of reactivity of the following compounds towards nucleophilic aromatic substitution ( S_NAr ): (I) (II) (III)

Step-by-step solution

Nucleophilic aromatic substitution ( S_NAr ) proceeds via an addition-elimination mechanism, forming a carbanion intermediate (Meisenheimer complex). The reactivity depends on two main factors: 1. The presence of electron-withdrawing groups (EWGs) at ortho and para positions, which stabilize the intermediate carbanion and increase reactivity. Conversely, electron-donating groups (EDGs) destabilize the intermediate and decrease reactivity. 2. The nature of the leaving group. For S_NAr , the reactivity order of halog