Among the following four compounds A. Phenol B. Methyl phenol C. meta-nitrophenol D. para nitrophenol the acidity order is

An electron withdrawing group (-I showing group like $\left.-\mathrm{NO}_2,-\mathrm{CN}\right)$ stabilises the phenoxide ion, thus when present, increases the acidity of phenol. On the other hand electron releasing groups ($+I$ showing group like $-\mathrm{CH}_3,-\mathrm{C}_2 \mathrm{H}_5$), when present, decrease the acidity of phenol by destabilising phenoxide ion. Hence, the correct order of acidity of given compounds is \(\underset{(D)}{\text{p-nitrophenol}} > \underset{(C)}{\text{m-nitrophenol}} > \underset{(A)}{\text{phenol}} > \underset{(B)}{\text{methyl phenol}}\) (due to intermolecular H -bonding)