Final answer:
The Environmental Protection Agency (EPA) is responsible for pesticide registration in the United States, in accordance with the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA).
Step-by-step explanation:
Pesticides in the United States are registered through the Environmental Protection Agency (EPA). This federal agency is in charge of administering the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and is responsible for the registration of all pesticides that are legally sold within the country. The decision for the correct choice is E) EPA, as it is the regulatory agency directly linked to pesticide oversight and regulation, whereas other agencies like the USDA and FDA have distinct roles in other aspects of public health and safety.