Match List I with List II Choose the correct answer from the...

${pK}_{a} = - {logK}_{a}$, here ${K}_{a}$ acid dissociation constant. More the ${K}_{a}$ value, stronger is the acidic nature of the respective acid.

Hence, the lower ${pK}_{a}$ value denotes a more powerful acid.  Phenols are more acidic than alcohols. Hence, ethanol has more ${pK}_{a}$ value. Nitro group is the electron withdrawing group, hence it increases the acidic nature of phenols.  Among the given phenols para nitrophenol  is stronger acid. The ${pK}_{a}$ values are matched below.

Ethanol $\to$$15 . 9$

Phenol$\to 10$

$m -$Nitrophenol $\to 8 . 3$

$p -$Nitrophenol$\to 7 . 1$

Hence, the answer is option D.