On increasing strength of ligand, wavelength of absorbed radiation decreases
Strength of ligands according to spectrochemical series is: $\mathrm{N}{\mathrm{H}}_3>{\mathrm{H}}_2\mathrm{O}>\mathrm{C}{\mathrm{l}}^{-}$
$\therefore \mathrm{ }$ Order of wavelength absorbed will be $\mathrm{C}{\mathrm{l}}^{-}>{\mathrm{H}}_2\mathrm{O}>\mathrm{N}{\mathrm{H}}_3$
$\therefore \mathrm{ }$ Correct order of wavelength absorbed is
$\mathrm{I}>\mathrm{I}\mathrm{I}>\mathrm{I}\mathrm{I}\mathrm{I}$