Which of the following is an example of physical contamination?

Physical contamination refers to the introduction of foreign objects into food that can cause harm or injury to consumers. In this context, pest droppings serve as a clear example of physical contamination because they are visible objects that can unintentionally mix with food. The presence of such contaminants can lead to foodborne illnesses; therefore, avoiding any physical contamination is critical for food safety.

In contrast, the other options relate to different types of contamination or do not fit the definition of physical contamination. Salmonella bacteria represent biological contamination, as they are microorganisms that cause foodborne illness. Silverware, while it can be considered a physical object, is typically not a contaminant when clean and used properly. Cooking oil is considered an ingredient and does not fall under the category of contaminants at all. Understanding these distinctions is crucial for identifying and managing food safety effectively.