The compound P, Q and Swere separately subjected to nitration using HNO3/H2SO4 mixture. The major product formed in each case respectively is

Product is w.r.t to –OH as this reaction is electrophilic substitution and OH group is activating.Product is w.r.t – OCH3 as it is more ring activating than CH3Benzene ring to which     O     || -C- is attached becomes deficient in electrons due to – R nature of group. Rather to which –O– is attached becomes e¯ rich due to lone pair so product will be on that ring.