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
Alginate fillers derived from 
Select and explain. 
A. Calcium sulphate, B. Sodium phosphate, C. Potassium alginate, D. Diatomaceous earth
D: Diatomaceous earth
Answer: D: Diatomaceous earth 
Explanation: None