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
Impression plaster containing potato starch is called: 
Select and explain. 
A. Plaster of paris, B. Soluble plaster, C. Anti — expansion solution, D. Die stones
B: Soluble plaster
Answer: B: Soluble plaster 
Explanation: None