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: Surgery
[{'content': 'For alveolar distraction adequate height of mandible needed is? \nSelect and explain. \nA. 4-6 mm, B. 6-8 mm, C. 8-10 mm, D. 10-12 mm', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]