Which of the following has highest reactivity towards nucleophilic substitution reaction involving cleavage of C - Cl bond?

Step-by-step solution

Electron-withdrawing groups at ortho and para positions enhance nucleophilic aromatic substitution by stabilizing the Meisenheimer complex through resonance. Chlorobenzene lacks electron-withdrawing groups and shows minimal reactivity. p-Nitrochlorobenzene has one nitro group at the para position, providing moderate stabilization. 2,4-Dinitrochlorobenzene features nitro groups at ortho and para positions, offering greater stabilization. 2,4,6-Trinitrochlorobenzene possesses three nitro groups at ortho and para posi