AIIMS 2019 Chemistry Basicity of Amines MCQ Question

Option C is correct because the methyl group (−CH₃) exhibits a +I (inductive) effect, which stabilizes the positive charge on the nitrogen atom in the compound, enhancing its ability to donate a lone pair of electrons and thus increasing its basic strength. The electron-donating nature of the methyl group reduces the overall electron deficiency of the nitrogen, making it a stronger base compared to the other options.

In contrast, options A, B, and D likely contain functional groups or structural features that either do not exhibit a +I effect or have electron-withdrawing characteristics that decrease basicity, such as halogens or carbonyl groups, which destabilize the nitrogen's lone pair and reduce its basic strength.