Which One of the Following Is a Redox Reaction?
A) $\to$

Which one of the following is a redox reaction?

A) 2Na(g) + Cl₂(g) $\to$ 2NaCl(s)
B) Ba²⁺(aq) + SO₄^2-(aq) $\to$ BaSO₄(s)
C) K₂Cr₂O₇(aq) + 2KOH(aq) $\to$ 2K₂CrO₄(aq) + H₂O(l)
D) Na₂CO₃(s) + 2HCl(aq) $\to$ 2NaCl(aq) + CO₂(g) + H₂O(l)
E) H₂O(l) $\to$ H⁺(aq) + OH^-(aq)