Which alloy contains $Cu$,$Sn$,and $Zn$?

List-$I$ contains different compounds formed during the extraction of metal $(M)$ in List-$II$. Match the compounds in List-$I$ with the corresponding metal and process in List-$II$.

List-$I$	List-$II$
$(P). [M(CN)_2]^-$	$(1). Ni$ (during refining of metal)
$(Q). [M(CO)_4]$	$(2). Ti$ (during refining of metal)
$(R). MI_4$	$(3). Pb$ (during roasting of ore)
$(S). MO$	$(4). Ag$ (during leaching of ore)

Match the following processes in List-$I$ with their respective applications in List-$II$:

List-$I$	List-$II$
$A$. Van Arkel method	$P$. Purification of titanium
$B$. Solvay process	$Q$. Manufacture of $Na_2CO_3$
$C$. Bassemerisation	$S$. Reduction of copper
$D$. Hall-Herault process	$R$. Reduction of aluminium

The major components of German Silver are:

What are the metals and their approximate percentages in German silver?

The correct statement$(s)$ related to processes involved in the extraction of metals is(are):
$(A)$ Roasting of Malachite produces Cuprite.
$(B)$ Calcination of Calamine produces Zincite.
$(C)$ Copper pyrites is heated with silica in a reverberatory furnace to remove iron.
$(D)$ Impure silver is treated with aqueous $KCN$ in the presence of oxygen followed by reduction with zinc metal.