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': 'According to Kaban’s protocol rate of distraction osteogenesis to regenerate a new ramus/ condyle unit is? \nSelect and explain. \nA. 1 mm/day, B. 1.5 mm/day, C. 2.0 mm/day, D. 2.5 mm/day', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]