Which one of the following ores is best concentrated by froth floatation method?

The concentration of sulfide ores such as zinc blend ( ZnS ), cooper pyrites ( 2 CuFeS ), galena ( PbS ), etc. is done by the froth floatation method. The main principle of froth floatation is the surface of sulfide ores are preferentially wetted by oils while that of the gauge is preferentially wetted by water. Extraction of Crude Metal from Concentrated Ore