Which of the Following Reactions Is an Oxidation-Reduction Reaction

Multiple Choice

Which of the following reactions is an oxidation-reduction reaction?

A) CaCO₃(s) + 2HCl(aq) → CaCl₂(aq) + H₂O(l) + CO₂(g)
B) NH₄NO₃(aq) → N₂O(g) + 2H₂O(l)
C) AgNO₃(aq) + KI(aq) → AgI(s) + KNO₃(aq)
D) CaO(s) + SO₃(g) → CaSO₄(s)
E) H₂SO₄(aq) + 2NaOH(s) → Na₂SO₄(aq) + 2H₂O(l)