Which entities are exempt from DEA registration but can prescribe, dispense, and administer controlled substances?

The correct choice highlights entities that operate under federal authority and are exempt from individual DEA registration requirements while still having the authority to prescribe, dispense, and administer controlled substances. Members of the armed forces, Public Health Service officers, and Bureau of Prisons personnel are all part of government entities that function under specific federal statutes and regulations. These professionals are authorized to handle controlled substances as part of their job functions without needing to obtain separate registrations with the DEA. This arrangement allows for coherent management of drug regulations across various federal sectors, ensuring that authorized personnel can effectively fulfill their roles in healthcare and law enforcement without additional bureaucratic barriers.

In contrast, the other options include individuals or groups that typically require individual or facility registrations with the DEA to prescribe or dispense controlled substances. For example, pharmacy interns, nurse practitioners, and physician assistants typically need to have a supervising physician's oversight or specific certifications to handle controlled substances. Likewise, drug enforcement agents and pharmaceutical researchers operate under specific regulatory frameworks that require them to work within the confines of the law concerning controlled substances. Pharmacists, emergency medical technicians, and home health aides do not have the same exempt status as the entities mentioned in the correct choice and generally require individual DEA registration to engage in the management of controlled substances.