Which process of purification is represented by the following scheme $\mathrm{Ti}_{\text{impure}} + 2\mathrm{I}_2 \xrightarrow{250^\circ \mathrm{C}} \mathrm{TiI}_4 \xrightarrow{1400^\circ \mathrm{C}} \mathrm{Ti}_{\text{pure}} + \mathrm{I}_2$

This purification involves formation of a volatile iodide of titanium at lower temperature and its decomposition at high temperature to deposit pure metal. That is the iodide process, also called the Van-Arkel process. The given reaction is: $$\mathrm{Ti}_{\text{impure}} + 2\mathrm{I}_2 \xrightarrow{250^\circ \mathrm{C}} \mathrm{TiI}_4$$ $$\mathrm{TiI}_4 \xrightarrow{1400^\circ \mathrm{C}} \mathrm{Ti}_{\text{pure}} + \mathrm{I}_2$$ Among the options, this matches $\text{Van-Arkel process}$.