GKFix MCQ Question

Why does Mn²⁺ exhibit a relatively low value for the standard electrode potential (E°) for M³⁺/M²⁺?

• A. The stability of the Mn³⁺ ion with a d⁴ configuration
• B. The instability of the Mn²⁺ ion with a d⁵ configuration
• C. High lattice energy of MnF₃
• D. The stability of the Mn²⁺ ion with a d⁵ configuration