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': 'Ossification center of upper end of ulna is united by: DNB 10 \nSelect and explain. \nA. 9 years, B. 11 years, C. 14 years, D. 16 years', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. 16 years', 'role': 'assistant'}]