Which of the following is correct?

Match the conversions in Column-$I$ with the type$(s)$ of reaction$(s)$ given in Column-$II$.

Column-$I$	Column-$II$
$A$. $PbS \rightarrow PbO$	$p$. roasting
$B$. $CaCO_3 \rightarrow CaO$	$q$. calcination
$C$. $ZnS \rightarrow Zn$	$r$. Carbon reduction
$D$. $Cu_2S \rightarrow Cu$	$s$. self reduction

What is the appropriate process for the extraction of lead from low-grade ore (impurity level is high)?

Metals are extracted by other methods through the formation of complexes. The complexes formed in these methods are: $I$: Cyanide process,$II$: Mond process,$III$: Photographic fixing process.

Which one of the following statements is incorrect?

Among statements $(a)-(d),$ the correct ones are
$(a)$ Limestone is decomposed to $CaO$ during the extraction of iron from its oxides.
$(b)$ In the extraction of silver,silver is extracted as an anionic complex.
$(c)$ Nickel is purified by Mond's process.
$(d)$ $Zr$ and $Ti$ are purified by Van Arkel method.