Which of the following is a characteristic of hepatitis viruses?

Hepatitis viruses are primarily known for affecting the liver, which is why the choice indicating they only affect the liver is accurate. This characteristic is fundamental to understanding the disease processes associated with these viruses. Hepatitis A, B, C, D, and E all impact liver health, leading to conditions ranging from asymptomatic infections to severe liver damage, such as cirrhosis or liver cancer.

While it's true that some hepatitis viruses, particularly hepatitis A and B, can have vaccine options available, not all types have an effective vaccine. For instance, there is no vaccine for hepatitis C or E. Additionally, hepatitis viruses do not get transmitted through respiratory droplets, and some can survive outside the body for extended periods, contradicting that they cannot survive outside. This underscores the specificity of the effects of hepatitis viruses on the liver, reinforcing why this characteristic stands out among the options provided.