The Virulence Factor of Vibrio Cholera, Which Is Primarily Responsible

The virulence factor of Vibrio cholera, which is primarily responsible for the signs and symptoms of cholera, is

A) its activation of certain genes within the human body.
B) its ability to produce a potent exotoxin.
C) the presence of polar flagella.
D) its ability to form biofilms in saltwater.
E) its ability to survive in freshwater.