Which of the Following Involves Reduction?
A)Ca²⁺(aq)+ CO₃^2-(aq) $\rarr$ CaCO₃(s)
B)2 H⁺(aq)+ SO₃^2-(aq)

Which of the following involves reduction?

A) Ca²⁺(aq) + CO₃^2-(aq) $\rarr$ CaCO₃(s)
B) 2 H⁺(aq) + SO₃^2-(aq) $\rarr$ H₂O(l) + SO₂(g)
C) VO₄^3-(aq) $\rarr$ VO²⁺(aq)
D) CrO₂^- (aq) $\rarr$ CrO₄^2-(aq)
E) 2 S₂O₇^2-(aq) + H₂O(l) $\rarr$ 2 SO₄^2-(aq) + 2 H⁺(aq)