n-propyl amine and isopropyl amine are examples of

Position isomers share the same molecular formula but different structural formula yet has different arrangement for functional groups.
${\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{CH}}_2{\mathrm{NH}}_2$ is n-propyl amine whereas ${\mathrm{CH}}_3-{\mathrm{CHNH}}_2-{\mathrm{CH}}_3$ represents isopropyl amine thus allowing all constraints for position isomerism only.
Thus, (A) position isomerism is the correct answer.