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 distraction of small bone segments rate of distraction should be? \nSelect and explain. \nA. 0.3 to 0.5 mm/day, B. 0.5 to 0.7 mm/day, C. 0.7 to 0.9 mm/day, D. 1.0 mm/day', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]