Which of the following describes a biological hazard?

A biological hazard is specifically defined as a threat that comes from living organisms, particularly microorganisms such as bacteria, viruses, parasites, and fungi. These agents can contaminate food, leading to foodborne illnesses. The presence of microorganisms in food poses a significant risk because they can multiply and produce toxins, creating health hazards if consumed.

While the other options present relevant concerns in food safety, they do not fall under the category of biological hazards. Pesticides and harmful chemicals represent chemical hazards, which involve substances that can cause adverse health effects through their chemical properties. Foreign objects, such as pieces of glass or metal, are classified as physical hazards, as they can cause injury or choking but are not biological in nature. Therefore, the presence of microorganisms in food is the only option that correctly identifies a biological hazard.