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 average root surface area of maxillary first molar is\n(in mm2) \nSelect and explain. \nA. 433, B. 431, C. 426, D. 400', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]