Answer: C, D
Diphenylamine has the lone pair shared with two rings, and 4-nitroaniline has an electron-withdrawing NOX2 group in para conjugation, so both are weaker than aniline. N-Methylaniline has a donating methyl group on nitrogen and is slightly stronger than aniline, and 4-methylaniline is also stronger because of the +I effect of CHX3.