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': 'Which of the following is the first proven vector of a virus disease? \nSelect and explain. \nA. Aedes aegypti, B. Anopheles stephensi, C. Anopheles culicifacies, D. Culex fatigans', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Aedes aegypti has an impoant position in the history of preventive medicine. It is the first proved vector of a viral disease. It causes yellow fever. Chapter: Environment and health Ref: Park 21st edition page: 711', 'role': 'assistant'}]