Directive Influence Of Substituents

The orientation of a second substituent on a benzene ring is controlled by the group already present. The nitro group, $-N{O}_2$, is strongly electron-withdrawing through both resonance and induction, which makes it a deactivating, meta-directing substituent. By withdrawing electron density, it destabilizes the arenium ion intermediates that would form on ortho and para attack more than the one formed on meta attack, because in ortho and para attack a positive charge lands directly on the carbon bearing the nitro group. Consequently the meta position is the least destabilized and becomes the major site of substitution. The option claiming ortho-para direction through activation is wrong because nitro is not an activating group. The para-only claim is incorrect because deactivating resonance-withdrawing groups direct meta, not para. The statement that no substitution occurs is false; the ring is simply less reactive but still reacts under forcing conditions. The reasoning can be visualised by drawing the resonance structures of the intermediate: for ortho and para attack one canonical form places a positive charge on the ring carbon already bearing the electron-poor nitro group, a highly unfavourable situation that does not arise for meta attack. This is the standard NCERT rule for directive influence and underlies the contrast with electron-donating groups that direct ortho-para. A consistency check: groups that pull electrons out of the ring almost always direct incoming electrophiles to the meta position.