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': 'Water powder ratio of dental stone and plaster is\nrespectively \nSelect and explain. \nA. 0.28 and 0.6, B. 0.6 and 0. 28, C. 0.6 and 3.2, D. 0.28 and 0.98', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]