Electrometallurgical process is used to extract

In a blast furnace,iron oxide is reduced by:

In the metallurgical process of aluminium,cryolite $(Na_3AlF_6)$ is mixed with alumina $(Al_2O_3)$ in its molten state,because it

Given are two statements,one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: Magnesium can reduce $Al_{2}O_{3}$ at a temperature below $1350^{\circ} C$,while above $1350^{\circ} C$ aluminium can reduce $MgO$.
Reason $R$: The melting and boiling points of magnesium are lower than those of aluminium.
In light of the above statements,choose the most appropriate answer from the options given below:

What is the role of cryolite in the metallurgy of aluminium?

Which among the following is used as flux in the extraction of iron from oxide ores?