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: Microbiology
[{'content': 'H N is: \nSelect and explain. \nA. Bird flu virus, B. Vaccine for HIV, C. Causative agent of Japanese encpehalitis, D. An eradicated virus', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) Bird flu virus which is a causative agent of bird flu. Majority of an influenza do not infect humans. However, an H5N1 is a strain with pandemic potential since it ultimately adapt into a strain that is contagious among humans.', 'role': 'assistant'}]