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: Forensic Medicine
[{'content': 'Rate of growth of beard hair is: September 2004 \nSelect and explain. \nA. 0.2 mm/day, B. 0.4 mm/day, C. 0.6 mm/day, D. 1 mm/day', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B i.e. 0.4 mm/ day', 'role': 'assistant'}]