Answer the following question given this paragraph: 

Viruses cause many human diseases. In addition to the diseases mentioned above, viruses cause rabies, measles, diarrheal diseases, hepatitis, polio, and cold sores (see Figure below ). Viral diseases range from mild to fatal. One way viruses cause disease is by causing host cells to burst open and die. Viruses may also cause disease without killing host cells. They may cause illness by disrupting homeostasis in host cells.


Q: What cause rabies, measles, diarrheal diseases, hepatitis, polio, and cold sores?

 Choices:

- parasites

- bacteria

- contaminants

- viruses

A:
viruses
