AIIMS 2018 Chemistry Nernst Equation MCQ Question

Option A is correct because it directly states the relationship between the standard electrode potential (E°) and the equilibrium constant (k) for the half-reaction involving B⁺, as given by the Nernst equation: E° = (0.059/n) log k, where n is the number of electrons transferred (n = 1 for B⁺ + e⁻ → B). The other options are incorrect because they either restate the equation without providing additional context (options B and C) or present an arbitrary value (option D) that does not relate to the given equations or their derived potentials. Understanding the relationship between E° and k is crucial for predicting the spontaneity of redox reactions.