Some meta- directing subsituents in aromatic substitution are given. Which one is most deactivating ?

Some meta- directing subsituents in aromatic substitution are given. W

1.	Some meta- directing subsituents in aromatic substitution are given. Which one is most deactivating ?
Answer» `-SO_(3)H` `-COOH` `-NO_(2)` `-C-=N` Solution :`-NO_(2)` GROUP is most DEACTIVATING group DUE to STRONG `-E` effect , `-I` effect and `-M` effect.