Consider the four chemical equations below.
I. Ca²⁺(aq) + CO₃²⁻(aq) → CaCO₃(s)
II. H⁺(aq) + OH⁻(aq) → H₂O(l)
III. Ba(OH)₂(aq) + H₂SO₄(aq) → BaSO₄(s) + 2 H₂O(l)
IV. Ag⁺(aq) + Cl⁻(aq) → AgCl(s)
Which equation(s) can simultaneously be classified as both an acid–base reaction and a precipitation reaction?
a) I and III only
b) III only
c) II only
d) II and III only