What type of microorganisms are considered biological agents?

Biological agents encompass a wide range of microorganisms and substances that can pose risks to human health, agriculture, or the environment. This category includes not just one type of microorganism, but a variety that can lead to biological hazards. The correct choice highlights the inclusion of viruses, toxins, and different types of microorganisms, which collectively contribute to the classification of biological agents.

Viruses are infectious agents that can cause diseases in humans and animals, making them significant as biological agents. Toxins, which can be harmful substances produced by microorganisms, also fall into this category, as they can cause adverse health effects when individuals are exposed to them. Additionally, bacteria and fungi, along with other pathogens, are integral components of the biological agents that are monitored and regulated due to their potential to cause infections or disease outbreaks. Therefore, the comprehensive inclusion of viruses, toxins, and microorganisms reflects a broader understanding of what constitutes biological agents.