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': 'Primary canine erupts: \nSelect and explain. \nA. After D, B. Before B, C. After B, D. After E', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]