Correct Answer - C
Due to the presence of electron rich methoxy group (+l) at p-position, the polarity increase on C-X bond by which it becomes more reactive towards nuclephilic attack of ethanol, p-nitro benzyl bromide are electron dificient group decrease the polarity of C-X bond. Hence by them it become difficult to react with ethanol due to less polarity. Methyl group is less electron rich than methoxy group.
