Which of the following methods is used to separate wolframite and stannic oxide present in cassiterite?

In the leaching method,bauxite ore is digested with a concentrated solution of $NaOH$ that produces $X$. When $CO_2$ gas is passed through the aqueous solution of $X$,a hydrated compound $Y$ is precipitated. $X$ and $Y$ respectively are

The froth floatation process used for the concentration of sulphide ore:

In the leaching of alumina from bauxite,the ore impurity expected to leach out in the process by reacting with $NaOH$ is:

Select the correct option regarding the method of separating two sulfide ores by the froth flotation process.
$(1)$ The ratio of water and oil is chosen appropriately.
$(2)$ Some depressants are used for this process.
$(3)$ $HCN$ is a depressant for a mixture of $ZnS$ and $PbS$.
$(4)$ By using a suitable depressant for a mixture of $ZnS$ and $PbS$,only $PbS$ comes up with the froth.

Which of the following ores can be concentrated by the froth flotation method?