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: Pathology
[{'content': 'The tooth most commonly involved in chronic focal sclerosing osteomyelitis is \nSelect and explain. \nA. Maxillary second molar, B. Maxillary third molar, C. Maxillary first molar, D. Mandibular first molar', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]