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': 'Most common accelerator in gypsum is \nSelect and explain. \nA. NaF, B. Aluminosilicate, C. Potassium sulphate, D. Potassium fluoride', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]