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
[{'content': 'Which is gypsum die hardener \nSelect and explain. \nA. Cyanoacrylate, B. Potassium sulphate, C. Calcium sulphate, D. Trisodium Phosphate', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]