What is the half-reaction that occurs at the anode of the following reaction: 2H⁺(s) + Sn(s) → Sn²⁺(aq) + H₂(g)?
a) 2H⁺ → H₂ + 2e⁻
b) Sn → Sn²⁺ + 2e⁻
c) 2H⁺ + 2e⁻ → H₂
d) Sn + 2e⁻ → Sn²⁺