Answer:
B. H⁺ and I
Step-by-step explanation:
Spectator ions are ions that appear in both the reactant and product of a chemical reaction. This ions remain unchanged on both sides of the chemical equation, they simply remain the same as the reaction occurs.
From the equation:
2H⁺ + SO₄²⁻ + Ca²⁺ + 2I⁻ ⇒ CaSO₄ + 2H⁺ + 2I⁻
you can see that H⁺ and I⁻ ions remain unchanged as the reaction occurs. This spectator ions can be removed to form a net ionic equation. Removing the spectator ions gives:
SO₄²⁻ + Ca²⁺ ⇒ CaSO₄