Which of the following is a type of harm caused by biological agents?

The correct answer, ethological harm, refers to the effects that biological agents can have on human health and the environment. Biological agents, such as bacteria, viruses, or other pathogens, can disrupt normal biological functions and lead to disease, infection, or other adverse health conditions. Ethological harm encompasses these impacts, as it deals with the behavior of living organisms and their interactions with each other and their surroundings.

In this context, the other options do not pertain to biological agents. Chemical harm involves exposure to toxic substances, resulting in detrimental effects primarily from their chemical nature rather than their biological activity. Mechanical harm pertains to physical injury caused by mechanical forces or impacts. Thermal harm results from exposure to extreme temperatures, causing burns or heat-related illnesses. Understanding these distinctions is crucial when identifying the specific types of harm associated with various hazardous materials.