To cause a human pandemic, the H5N1 avian flu virus would have to

(A) spread to primates such as chimpanzees.

(B) develop into a virus with a different host range.

(C) become capable of human-to-human transmission.

(D) become much more pathogenic.

Asian highly pathogenic avian influenza virus (H5N1) is a deadly virus that disseminates mostly in birds. It is highly infectious among poultry birds. It was detected in humans in 1997 in Hong Kong when it became endemic in poultry. Since then, it has been discovered in more than 50 countries.

H5N1 virus became a human pandemic when it was transmitted from birds to human beings. After the first infection of a human from birds in 1997, it increased the mortality rate by more than 50 percent.

Thus,H5N1 became a pandemic when it was transmitted to humans from the birds.

Therefore, the given statement is false.

H5N1 became pandemic when it was transmitted to different hosts but did not develop into a new virus. If it evolves, it can produce a global health threat that could be more debilitating than the pandemic it caused.

Thus,H5N1 did not develop into a virus that has a wide range of hosts.

Therefore, the given statement is false.

In order to cause the pandemic in humans, the virus H5N1 virus got transmitted from human to human, and the mortality rate due to this virus is more than 50 percent.

Thus, thepandemic due to H5N1 was due to human transmission.

Therefore, the given statement is true.

H5N1 is a highly pathogenic virus that was carried in birds, posing a long-term threat. So it did not need to become more pathogenic to cause the pandemic in human beings.

Thus, H5N1 did not become more pathogenic to cause a pandemic.

Therefore, the given statement is false.