Final answer:
A DEA license is required for all veterinarians that prescribe, order, or dispense controlled substances.
Step-by-step explanation:
The correct answer is C) DEA. A DEA license is required for all veterinarians that prescribe, order, or dispense controlled substances. The Drug Enforcement Administration (DEA) is responsible for enforcing the controlled substances laws and regulations in the United States. They regulate the manufacturing, distribution, and dispensing of drugs, including controlled substances.