For Using electrolysis to extract metals, which reaction focus answer best supports this Unit 4.4 objective: (HT only) Write half equations for aluminium ion reduction and oxide ion oxidation when formulae and charges are supplied?

The correct option is To allow ions to move freely - correct reaction focus for only.

The correct option is To allow ions to move freely - correct reaction focus for only. To allow ions to move freely - correct reaction focus for only is correct because it directly supports the approved learning objective to (HT only) Write half equations for aluminium ion reduction and oxide ion oxidation when formulae and charges are supplied. This reaction focus variant asks students to separate only from similar Unit 4.4 chemical-change ideas. The reasoning belongs to Using electrolysis to extract metals within Electrolysis, so it should not be confused with nearby ideas about acids, alkalis, bases, oxidation, reduction, displacement, reactivity, electrolysis, electrodes, ions, pH, or salt preparation unless those are named in the objective. Use the focus term only to keep the answer aligned with AQA GCSE Chemistry 8462 Unit 4.4 Chemical changes. Keep acid, alkali and base distinct; keep oxidation and reduction distinct; do not mix reduction with displacement; keep electrolysis separate from electroplating; distinguish anode from cathode, positive ions from negative ions, oxidation state from ionic charge, and strong acid from concentrated acid. The other options are weaker because they either use the wrong reaction type, wrong ion, wrong electrode, wrong acid-base distinction, vague wording, or the wrong chemical-change context.