At present following types of influenza viruses are circulating in the world, except ?

Ans. is 'c' i.e., H5N, At present three types of influenza viruses are circulating in the world: A(H/N1), A (H3N2) and B viruses. WHO global surveillance activities have identified human infection with a new influenza virus called A ) in Hong Kong in mid1997. However, the possibility that the outbreak heralded a global influenza pandemic did not materialize.