They make sure medicines do what they claim to do.
The most likely item to be on Enzo's list is: "They make sure medicines do what they claim to do."
The most likely response to be on Enzo's list of responsibilities for the FDA is "They make sure medicines do what they claim to do." The FDA, or the U.S. Food and Drug Administration, is responsible for regulating and ensuring the safety and efficacy of drugs, medical devices, vaccines, food products, cosmetics, and other health-related products. They oversee the process of drug development, approval, and post-market surveillance to ensure that medicines meet the required standards and are safe for public use. For Enzo's list, this responsibility of the FDA would be the most relevant and significant.