Which method of purification is represented by the following equation : <Br> $Ti(s) + 2I_2 (g) \xrightarrow{523 K} TiI_4 (g) \xrightarrow{1700 K} Ti(s) + 2I_2 (g)$

Question

( A ) Van Arkel
( B ) Zone refining
( C ) Poling
( D ) Cupellation