Which agency registers drug training aids?

The Drug Enforcement Agency (DEA) is responsible for registering drug training aids due to its role in regulating controlled substances and preventing drug-related issues. This agency oversees matters related to the enforcement of the controlled substances laws and regulations of the United States. It ensures that training aids used in law enforcement and drug education programs are compliant with federal regulations, thus contributing to effective drug enforcement and prevention strategies.

In contrast, the other agencies listed have different primary missions. The Federal Bureau of Investigation (FBI) focuses on broader federal criminal investigations and domestic intelligence, the Department of Homeland Security (DHS) primarily addresses national security and immigration issues, and the Central Intelligence Agency (CIA) is responsible for foreign intelligence and national security operations. None of these agencies handle the registration of drug training aids as part of their core functions, underscoring why the DEA is the correct response.