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': 'How many pulpal horns are there in the mandibular second primary molar? \nSelect and explain. \nA. 3, B. 6, C. 4, D. 5', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]