Consider the following species

I)  

II)

III)

IV) 

Incorrect statement is

Hint: Group which contains atleast one electronegative atom like F, Cl, O N etc., are acting as –IE groups and exhibits –I effect.

→ In a molecule when both mesomeric and inductive effevts simultaneously operating then mesomeric effect is predominant than inductive effect.

$\therefore$"OH" group in phenol mainly acts as electron donating group by +ME and hence it increases the electron density in benzene ring.

NH₃ group shows only –I effect but donot exhibits –M effect [due to lack of lonepair on "N"] and decreases the electron density in benzene ring.

$\therefore$attack of electrophile on benzene ring of anilinium ion decreases.

i.e., NH₃ deactivates the benzene ring by –I effect towards electrophile.