Which of the following is an example of possible cross-contamination?

Cross-contamination occurs when harmful microorganisms are transferred from one food item to another, which can result in foodborne illnesses. Each of the scenarios presented involves a situation where cross-contamination can take place.

The scenario involving raw chicken dripping onto raw beef illustrates a classic case of cross-contamination, as the juices from the raw chicken can carry bacteria like Salmonella, which can contaminate the beef.

Using a cutting board to trim pork and then chopping lettuce without cleaning the board reflects another form of cross-contamination. The bacteria present on the cutting board from the pork can easily transfer to the lettuce, which is often consumed raw.

Lastly, the situation with uncooked shrimp being de-veined above potato salad also represents cross-contamination. Any bacteria present on the shrimp could drip into the potato salad, contaminating it, especially since the salad is typically served without cooking, which would not kill those bacteria.

Since all these scenarios illustrate how cross-contamination can or does occur, the answer that encompasses all of them is indeed the most appropriate choice. Recognizing each example helps reinforce the importance of using proper food safety practices to prevent cross-contamination in a food service environment.