This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Contraceptives, Subject name: Gynaecology & Obstetrics
[{'content': "In CuT 200, '200' stands for: \nSelect and explain. \nA. Effective for 200 weeks, B. Surface area of copper in sq.mm, C. Weight in milligrams, D. Amount of copper released in mcg per day", 'role': 'user'}, {'content': "Answer: B \nExplanation: In CuT 200, the '200' expression means that the copper poion has an exposed surface area of 200 sq.mm.", 'role': 'assistant'}]