`NaCN` used in the froth floatation method for the purification of ore is

Options

A. `ZnS` which contain `PbS`
B. `Cu_(2)S `which contain `Fe_(2)S_(3)`
C. `PbS` which contain `ZnS`
D. `PbS` which contain `SiO_(2)`

Answer

C

Explanation

`ZnS` can form soluble complex with `NaCN`