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
Binder used in Gypsum investment is 
Select and explain. 
A. Silica, B. Quartz, C. Cristobolite, D. Calcium sulphate monohydrate
D: Calcium sulphate monohydrate
Answer: D: Calcium sulphate monohydrate 
Explanation: None