Bacteria Cause Diseases in Humans When They

Bacteria cause diseases in humans when they

A) rearrange the genes of the host to code for specific virulence factors that determine the type and extent of the illness.
B) carry the same genes as the host organism, causing them to be indistinguishable from the host cell.
C) carry the genes that code for virulent factors, causing them to be harmful to humans.
D) carry genes that allow them to become symbiotes.
E) carry the genes of organisms like birds (bird flu) or pigs (swine flu) .