Which of the following is a correct procedure for serving food?

The procedure of re-using unopened individually packaged ketchup packets is correct because these items are hermetically sealed, which means they are protected from contamination before they are opened. As long as the packets remain unopened, they can be safely served to other customers. This practice adheres to food safety regulations that prioritize health and hygiene by minimizing the risk of cross-contamination.

In contrast, re-serving unfinished salsa from another customer presents health risks because the salsa could have been contaminated once it was initially served. Likewise, re-serving untouched food that was returned could pose similar hazards, even if it appears fine because it has been previously handled by someone else. Re-using garnishes also creates a risk of cross-contact and contamination, as these items may have come into contact with other food items or surfaces. Thus, serving unopened ketchup packets is the only option that meets proper food safety protocols.