GKFix MCQ Question

For the reaction CaCO₃(s) ⇌ CaO(s) + CO₂(g), what is Kp equal to?

• A. [CaO][CO₂]/[CaCO₃]
• B. Kp = 1/p_CO₂
• C. p_CO₂
• D. [CO₂]