Disproportionation Is a Reaction in Which a Substance Is Both

Disproportionation is a reaction in which a substance is both oxidized and reduced in the reaction.Which is a disproportionation reaction?

A) ClO₃^-(aq) + 3 Cu(s) + 6 H⁺(aq) → Cl^-(aq) + 3 Cu²⁺(aq) + 3 H₂O(l)
B) ClO^-(aq) + Pb(OH) ₄^-(aq) → Cl^-(aq) + PbO₂(s) + H₂O(l) + 2 OH^-(aq)
C) 6 Cl^-(aq) + Cr₂O₇^2-(aq) + 14 H⁺(aq) → 3 Cl₂(g) + 2 Cr³⁺(aq) + 7 H₂O(l)
D) Cl₂(g) + 2 OH^-(aq) → Cl^-(aq) + ClO^-(aq) + H₂O(l)