Which method of purification is represented by the following equation?

Ti(s)+2I2(g)523k→TiI4(g)Til4(g)1700k→Ti(s)+2I2(g)This process is also known as Van Arkel method. It is used for refining Zirconium or Titanium. In this method, oxygen and nitrogen present as impurity are removed by heating metal in an evacuated vessel with iodine.Hence, option D is correct.