$Aluminium$ oxide is not reduced by chemical reactions since:

In which of the following production processes is limestone $(CaCO_3)$ $NOT$ used?

Among the following,the main reactions occurring in the blast furnace during the extraction of iron from haematite are:
$i$. $Fe_2O_3 + 3CO \rightarrow 2Fe + 3CO_2$
$ii$. $FeO + SiO_2 \rightarrow FeSiO_3$
$iii$. $Fe_2O_3 + 3C \rightarrow 2Fe + 3CO$
$iv$. $CaO + SiO_2 \rightarrow CaSiO_3$

Identify the reaction that does not take place during the smelting process of copper extraction.

Explain the electrolytic reduction of alumina.

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R).$
Assertion $(A):$ Aluminium is extracted from bauxite by the electrolysis of a molten mixture of $Al_2O_3$ with cryolite.
Reason $(R):$ The oxidation state of $Al$ in cryolite is $+3$.
In the light of the above statements,choose the most appropriate answer from the options given below: