Which of the following does the FDA Adverse Event Reporting System (FAERS) primarily deal with?

The FDA Adverse Event Reporting System (FAERS) is specifically designed to collect and analyze information about adverse events and medication errors related to drugs that are already on the market. This system serves as a crucial tool for monitoring the safety of drugs and identifying potential safety concerns after they have been approved for public use. By gathering reports from healthcare professionals, patients, and manufacturers, FAERS enables the FDA to assess the risk associated with various medications and take necessary actions, such as updating labeling, restricting use, or even withdrawing drugs from the market if the risks outweigh the benefits.

In contrast, the other options listed pertain to aspects that are outside the primary focus of FAERS. The assessment of marketing strategies, funding for research, and drug promotion through social media do not directly involve adverse event reporting or patient safety monitoring, which is the cornerstone of the FAERS mission. Thus, the emphasis on adverse event reports and medication error reports firmly establishes why this choice accurately reflects the main function of FAERS.