The correct sequence of steps involved in mononitration of aniline is

-NH₂ group is a highly activation group toward ESR. Even in presence less polar solvents (or) even in presence of non-polar solvent, aniline gives poly substituted products. To control the reactivity of aniline it is converted to acetanilide.

-NH-CO-CH₃ group is moderately activating group. Tis is because the lone pair of electrons of nitrogen atom are not only localized on benzene ring but also on -COR group.