Which of the following is used to tenderize meat?

Marinades are commonly used to tenderize meat because they typically contain acidic ingredients such as vinegar, citrus juice, or wine. These acids help break down the tough fibers in meat, making it more tender and flavorful. Additionally, marinades often include other ingredients like oils and various seasonings that enhance the overall taste. The process of marinating not only softens the meat but also allows the flavors to penetrate, resulting in a more savory dish when cooked.

Salt, while it can enhance flavor and draw moisture from the meat, does not have the same tenderizing effect as a marinade. Sugar primarily serves to balance flavors and add sweetness rather than to tenderize. Pepper is mainly used as a spice for flavoring and does not contribute to the tenderness of meat either. Therefore, marinades stand out as the most effective option for tenderizing meat among the choices provided.