In the isolation of which one of the following metals from their ores,is the use of cyanide salt not commonly involved?

Which one of the following oxides is reduced by water gas to obtain the metal during its extraction?

How is copper extracted from low grade copper ores?

Which one of the following metals is extracted by thermal reduction process?

Observe the following statements:
Statement-$I$: The choice of reducing agent for the reduction of an oxide ore can be predicted by using Ellingham diagram,a plot of $\Delta G^{\ominus}$ vs $T$.
Statement-$II$: According to Ellingham diagram,metal oxide with higher $\Delta G^{\ominus}$ is more stable than the oxide with lower $\Delta G^{\ominus}$.

Flux is used to remove