Which of the following is classified as a biological hazard?

Biological hazards refer to harmful organisms or substances that can cause foodborne illnesses or infections through food contamination. Parasites are a prime example of biological hazards, as they are living organisms that can invade host bodies, often through contaminated food or water. When food is improperly handled, prepared, or cooked, these parasites can survive and infect consumers, leading to various health issues.

Nails, copper pots, and dust do not fall under the category of biological hazards. Nails are physical hazards that can cause injury but do not lead to foodborne illnesses. Copper pots, while having some implications in terms of chemical hazards if not properly treated or maintained, are not considered biological hazards. Dust may carry contaminants, but it is not classified as a biological hazard since it is not a living organism or pathogen. Thus, parasites stand out in this context as they directly relate to biological dangers associated with food safety.