# For the diazonium ions that order of reactivity towards diazo-coupling with phenol in the presence of dilute $NaOH$ is:A.$I < IV < II < III$B.$I < III < IV < II$C.$III < I < II < IV$D.$III < I < IV < II$

We must know that the electron donating groups are referred to as activating groups, though steric effects could inhibit the reaction. An electron withdrawing group has the contradictory effect on the nucleophilicity of the ring. The electron withdrawing group takes away electron density from a $\pi$ system, thereby making it less reactive during this kind of reaction and thus called as deactivating groups.
Therefore, the order of the reactivity is $I < III < IV < II$ . Option (B) is correct.