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': 'Age of marriage of mentally retarded girl is: UP 09 \nSelect and explain. \nA. 16 years, B. 18 years, C. 21 years, D. Cannot marry', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. Cannot marry', 'role': 'assistant'}]