Brazil has recently confirmed cases of highly pathogenic avian influenza (HPAI) in wild birds. Avian influenza is mainly caused by:

(a) bacteria

(b) fungus

(c) virus

(d) parasite

Ans.(c)

Sol. Avian influenza (also known as bird flu) is a highly contagious viral disease that primarily affects birds, but some strains can also infect humans.