Which organization regulates the practice of pharmacy in the United States?

The correct answer is the Food and Drug Administration (FDA), which regulates the practice of pharmacy in the United States primarily through its authority over pharmaceutical drugs and the approval process for new medications. The FDA ensures that drugs are safe and effective for public use by evaluating data from clinical trials, overseeing the manufacturing processes, and monitoring the labeling of medications.

While other organizations listed have important roles in related areas, their functions do not directly involve regulating the practice of pharmacy. The World Health Organization focuses on international public health, the Federal Trade Commission deals with consumer protection and trade practices, and the Drug Enforcement Administration primarily addresses the regulation of controlled substances and enforcement related to drug trafficking and abuse. Thus, the FDA's comprehensive regulatory responsibilities make it central to the oversight of pharmacy practice in the U.S.