Match the reactions given in column(I) with the appropriate method(s) listed in column (II).
`{:("Column-I","Column-II"),((A)4 Au+8 NaCN+ 2 H_2O+O_2("air")to4 Na[Au(CN)_2]+4NaOH,(p)"Leaching"),((B)CuFeS_2+2 H_2SO_4toCuSO_4+FeSO_4+2 H_2O,(q)"Smelting"),(( C)Fe_2O_4+4 COoverset(823K)to3 Fe+4CO_2,(r)"Roasting"),((D) MgCl_2. 6H_2O underset("Dry" HCl(g))overset(Delta)toMgCl_2+6H_2O,(s)"Calcination"),(" ",(t)"Hydrometallurgy"):}`