What does the Federal Trade Commission (FTC) regulate?

The Federal Trade Commission (FTC) primarily regulates advertising for both prescription and over-the-counter (OTC) medications to ensure that all advertising is truthful, not misleading, and substantiated by appropriate evidence. This regulation falls under the FTC's authority to prohibit deceptive acts or practices in commerce, which includes the promotion of OTC drugs. The FTC's role is crucial as it aims to protect consumers by ensuring that they receive accurate information about the products being advertised, thus enabling them to make informed choices.

In the context of advertising for OTC drugs, the FTC enforces regulations that differ from those governing prescription medications, which are primarily overseen by the Food and Drug Administration (FDA). The regulations help maintain fairness in advertising and prevent misleading claims that can harm consumers. This makes option B the most accurate choice among the provided alternatives, as it directly aligns with the FTC's responsibilities on a broad scale in the context of drug promotion.

Other areas mentioned, such as advertising for prescription medications, promotion of health supplements, or pricing strategies of pharmacies, fall under different regulatory bodies or frameworks, which would not accurately represent the FTC's scope of work in the context of the question asked.