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': 'Breteau index is used for \nSelect and explain. \nA. Aedes, B. Anopheles, C. Hook  - worm infection, D. Hard tick', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]