Match items of Columns I with the items of Columns II and assign the correct code.

Column I	Column II
A.Cyanide process	1.Ultrapure Ge
B. Froth floatation process	2.Dressing of ZnS
C.Electrolytic reduction	3.Extraction of Al
D.Zone refining	4.Extraction of Au
	5.Purification of Ni

• A

  B

  C

  D

    2       3     1     5

• A

  B

  C

  D

    1      2      3     4

• A

  B

  C

  D

     3     4      5     1

• A

  B

  C

  D

     4      2     3     1

D.

Cyanide process is used for extracting Au (gold) from low-grade ore by converting the Au to the water soluble coordination complex.
Froth flotation process is used for the dressing of sulphide ore such ZnS.
Electrolytic reduction is used for the extraction of Al. The extraction of aluminium is carried out in a steel tank lined inside with graphite. Here graphite used serves as a cathode.
Zone refining is used for ultra pure Ge element. An ingot of Ge is first purified by zone refining. Then a small amount of antimony is placed in the molten zone which is passed through the pure Ge with the proper choice of rate of heating and other variables.