Answer:
The correct option is;
a. BaSO4.
Explanation:
a. BaSO₄ Insoluble
From the solubility table, we have all sulfates SO₄ are soluble except those of Sr²⁺, Ag⁺, Ca²⁺ ,Pb²⁺ Ba²⁺, Hg²⁺
b. KNO₃ Soluble
All nitrates are soluble, no exceptions
c. Na₂SO₄ Soluble
Sodium sulfate is among the soluble sulfates.
d. Li₂CO₃ Soluble
All carbonates are insoluble except those of NH₄⁺ and group IA.
