We Might Expect Virulence of a Particular Human Pathogen to Decrease

Multiple Choice

We might expect virulence of a particular human pathogen to decrease:

A) when opportunities for transmission are limited.
B) when opportunities for transmission are abundant.
C) when animal reservoirs for the pathogen are scarce.
D) in very large human populations, such as a large city.
E) when it uses insect vectors for transmission.