The mixing of which pair of reactants will result in a precipitation reaction?
a. CsI(aq) + NaOH(aq)
b. HCl(aq) + Ca(OH)₂(aq)
c. Na₂SO₄(aq) + RbNO₃(aq)
d. KNO₃(aq) + NH₄F(aq)