Which of the following orders correctly represent the strength of ligands in the spectrochemical series?
I. $\text{I}^- \lt \text{Br}^- \lt \text{S}^{2-} \lt \text{SCN}^-$
II. $\text{H}_2\text{O} \lt \text{NCS}^- \lt \text{NH}_3 \lt \text{en}$
III. $\text{Cl}^- \lt \text{F}^- \lt \text{N}^{3-} \lt \text{OH}^-$