Copper sulphate is commercially made from copper scraps 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:

What is the reduction of $Cr_2O_3$ by heating it with aluminum called?

During the electrolytic reduction of alumina,two auxiliary electrolytes $X$ and $Y$ are added to increase the electrical conductance and lower the melting point of the mixture. $X$ and $Y$ are:

Which method is used to obtain $Al$ from $Al_2O_3$?

Which of the following metals can be obtained by using $Al$ as a reducing agent?