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.

• A
  $B, C, A$
• B
  $B, C, D$
• C
  $B, C$
• D
  $C, D$