Which of the following pairs is correctly matched?

The zone refining method is used to obtain.......

When an alloy of silver and lead is rich in silver,which process is used for purification?

On which principle does the zone refining method work?

Which refining process is represented by the equation $Ti_{(s)} + 2I_{2(g)}$ $\xrightarrow{523 \ K} TiI_{4(g)}$ $\xrightarrow{1700 \ K} Ti_{(s)} + 2I_{2(g)}$?

Identify the statements which are not correct.
$a)$ Copper is refined by Van-Arkel method
$b)$ Zinc is refined by electrolysis method
$c)$ Zirconium is refined by distillation method