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': "The advantage of unfilled methyl methacrylate is that: \nSelect and explain. \nA. It can be finished smoothly, B. It has a low degree of flow, C. It's non-irritation to pulp, D. It's wear resistant is high", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]