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 of the following permanent tooth is least extracted for orthodontic treatment? \nSelect and explain. \nA. Canines, B. Maxillary first permanent molar, C. 1st molar, D. 2nd molar', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The teeth least commonly extracted is canine.', 'role': 'assistant'}]