Three complexes, $\quad\left[\mathrm{CaCl}\left(\mathrm{NH}_3\right)_5\right]^{2+}(\mathrm{I})$, $\left[\mathrm{Ca}\left(\mathrm{NH}_3\right)_5 \mathrm{H}_2 \mathrm{O}\right]^{3+}(\mathrm{II})$ and $\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}$ (III) absorb light in the visible region. The correct order of the wavelength of light absorbed by them is: