Source of infection: people or animals that can spread the pathogen. Transmission pathway: the pathogen leaves the infectious agent to reach healthy people through the pathway called transmission, such as airborne, foodborne, biological media transmission. Susceptible people: lack of immunity to a certain infectious disease and susceptible to infection of the disease is called susceptible people. Hepatitis A epidemic, the source of infection should be the people suffering from hepatitis A, and arkshell is just a carrier of hepatitis A virus, belongs to the transmission pathway in the biological media, so option C is correct.

Select: C

.