Which among the following substituent groups decreases the acidic strength of aromatic carboxylic acid?

Step-by-step solution

- NH ₂ is electron donating group which activate the benzene ring to electrophilic attack and make aromatic carboxylic acids less acidic. While - Cl ,- CN and - NO ₂ are electron withdrawing groups which increases the acidity of aromatic carboxylic acids.