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': 'When viewed occlusally, a primary mandibular second molar closely resembles which of following mandibular teeth? \nSelect and explain. \nA. Permanent second molar, B. Permanent first molar, C. Second premolar, D. Primary first molar', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]