Aluminium is obtained by electrolysing molten aluminium oxide. Which equation correctly represents the reaction taking place at the positive electrode?
- A$\text{Al} \rightarrow \text{Al}^{3+} + 3e^-$
- B$\text{Al}^{3+} + 3e^- \rightarrow \text{Al}$
- C$\text{O}_2 + 4e^- \rightarrow 2\text{O}^{2-}$
- D$2\text{O}^{2-} \rightarrow \text{O}_2 + 4e^-$