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: Social & Preventive Medicine
[{'content': 'In Cu T-200, the number denotes- \nSelect and explain. \nA. Surface area, B. Weight in microgram, C. Weight in miligram, D. Effective half life in week', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]