Which method is used for the refining of silver containing lead as an impurity?

On which principle does the zone refining method work?

Formation of $Ni(CO)_4$ and its subsequent decomposition into $Ni$ and $CO$ (recycled) forms the basis of the Mond process.
$Ni + 4CO$ $\xrightarrow{T_1} Ni(CO)_4$ $\xrightarrow{T_2} Ni + 4CO$
$T_1$ and $T_2$ are:

Match the following List-$I$ (Method) with List-$II$ (Metal refined):

List-$I$ (Method)	List-$II$ (Metal refined)
$(A)$ Zone refining	$(I)$ $Sn$
$(B)$ Liquation	$(II)$ $In$
$(C)$ Vapour phase refining	$(III)$ $Zn$
$(D)$ Distillation	$(IV)$ $Zr$
-	$(V)$ $Al$

The correct answer is:

Zone refining is used for the purification of

The poling process is used when the metal contains: