The acidity of compound I is due to delocalization in the conjugate base.
The conjugate base of compound IV is aromatic.
Compound II becomes more acidic, when it has a -NO2 substituent.
The acidity of compounds follows the order I >IV>V>II>III.
A. is a conjugate base of compound I Which is stabilized by delocalization or resonance.
B. is a conjugate base of, which is an aromatic compound.
C. –NO2 group is a strong electron-withdrawing group, which increases the acidic strength of compound II.
D. The order of acidic strength.