GKFix MCQ Question

What is the oxidation half-reaction in the reaction between Fe^2+ and Cr2O7^2– in acidic medium?

• A. Cr2O7^2– → Cr^3+
• B. Fe^2+ → Fe^3+
• C. Cr^3+ → Cr2O7^2–
• D. Fe^3+ → Fe^2+