Which of the following chemical reactions represents Hall-Heroult Process?
\( \mathrm{Cr_2O_3} + 2\mathrm{Al} \rightarrow \mathrm{Al_2O_3} + 2\mathrm{Cr} \)
\( 2\mathrm{Al_2O_3} + 3\mathrm{C} \rightarrow 4\mathrm{Al} + 3\mathrm{CO_2} \)
\( \mathrm{FeO} + \mathrm{CO} \rightarrow \mathrm{Fe} + \mathrm{CO_2} \)
\( 2[\mathrm{Au(CN)_2}]^-_{(aq)} + \mathrm{Zn}(s) \rightarrow 2\mathrm{Au}(s) + [\mathrm{Zn(CN)_4}]^{2-} \)