This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Dental
In heavy calculus formers, early plaque consists of Ca, PO4 and k in what proportions: 
Select and explain. 
A. Calcium > phosphorous > potassium, B. Phosphorous > potassium > calcium, C. Phosphorous > calcium > potassium, D. Potassium > phosphorous > calcium
C: Phosphorous > calcium > potassium
Answer: C: Phosphorous > calcium > potassium 
Explanation: None