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': 'The screening method of choice in an area where the prevalence of leprosy is 1/1000 is - \nSelect and explain. \nA. Contact survey, B. Group survey, C. Mass survey, D. Any of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]