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 mesial surface of the crown is almost parallel to long axis and the root of a: \nSelect and explain. \nA. Maxillary 1st premolar, B. Mandibular 2nd Premolar, C. Maxillary canine, D. Mandibular canine', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]