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: Gynaecology & Obstetrics
[{'content': 'Infra uterine copper T 200 is called copper 200 because : \nSelect and explain. \nA. Cotain 200 mgs of copper, B. Has 200 sq. mm. of copper, C. Has 200 copper turns, D. Can be retained for 200 days', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Has 200 sq. mm. of copper', 'role': 'assistant'}]