Final answer:
The Food and Drug Administration (FDA) is the agency that regulates the development and sale of all prescription and over-the-counter drugs.
Step-by-step explanation:
The agency that specifically regulates the development and sale of all prescription and over-the-counter drugs is the Food and Drug Administration (FDA). The FDA is responsible for protecting and promoting public health by regulating and supervising the safety, efficacy, and labeling of drugs. This includes approving new drugs, conducting safety inspections, and monitoring drug advertising and promotion.