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': 'Four carpal bones are present at what age: DNB 09 \nSelect and explain. \nA. 3 years, B. 4 years, C. 5 years, D. 6 years', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. 4 years', 'role': 'assistant'}]