The extraction of zinc from zinc blende is achieved by

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A:$ In an Ellingham diagram,the oxidation of carbon to carbon monoxide shows a negative slope with respect to temperature.
Reason $R:$ $CO$ tends to get decomposed at higher temperature.
In the light of the above statements,choose the correct answer from the options given below:

In the extraction of iron using a blast furnace,to remove the impurity $(X)$,chemical $(Y)$ is added to the ore. $X$ and $Y$ are respectively

Which metal cannot be extracted by the smelting process?

Which process of reduction of mineral to the metal is suited for the extraction of copper from its ores with low copper content?

Explain the extraction of elements by oxidation.