Which of the following ores is concentrated by the leaching process?

Which one of the following statements is true about the froth flotation method?

The ore which is concentrated by wetting with oil is:

How is leaching carried out in case of low grade copper ores?

Reagent used in Bayer's process of concentration of bauxite ore is:

Given below are two statements :-
Statement $I$: In froth floatation method,a rotating paddle agitates the mixture to draw air into it.
Statement $II$: Iron pyrites are generally avoided for the extraction of iron due to environmental reasons.
In the light of the above statements,choose the correct answer from the options given below :-