Which of the following is NOT a disease-causing agent for zoonotic diseases?

• A. Biologics
• B. Viruses
• C. Fungi
• D. Parasites

Answer: (A)

Zoonotic diseases come from infectious agents that can move from animals to humans. The main types you need to recognize are viruses, fungi, and parasites, all of which can be transmitted from animals and cause disease in people. Biologics are therapeutic or diagnostic products derived from living organisms—such as vaccines or antibody preparations—not infectious pathogens. They are not disease-causing agents in the context of zoonoses, so biologics are the correct choice for something that is NOT a disease-causing agent for zoonotic diseases.