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
H N is: 
Select and explain. 
A. Bird flu virus, B. Vaccine for HIV, C. Causative agent of Japanese encpehalitis, D. An eradicated virus
A: Bird flu virus
Answer: A: Bird flu virus 
Explanation: 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.