GKFix MCQ Question

What is the correct expression for the solubility product of iron(II) sulfide (FeS)?

• A. Ksp = [Fe²⁺]²[S²⁻]
• B. Ksp = [Fe⁺][S²⁻]
• C. Ksp = [Fe³⁺][S²⁻]
• D. Ksp = [Fe²⁺][S²⁻]