Who is responsible for enforcing regulations on occupational radiation safety?

The Occupational Safety and Health Administration (OSHA) is the correct choice because it is the primary agency responsible for ensuring safe and healthful working conditions for workers across the United States, which includes regulations pertaining to occupational radiation safety. OSHA sets and enforces standards that protect workers from hazards, including radiation exposure in various workplaces, such as medical facilities and research laboratories. Their regulations are designed to minimize risks and ensure that employers follow safety protocols to protect their employees from occupational hazards.

In contrast, the Federal Bureau of Investigations (FBI) focuses on national security and law enforcement and does not have a role in occupational safety regulations. The Nuclear Energy Institute (NEI) represents the nuclear energy industry and provides information and guidance but does not enforce safety regulations. The Centers for Disease Control and Prevention (CDC) primarily deals with public health issues and disease control, rather than directly enforcing occupational safety regulations. Thus, OSHA is the agency specifically dedicated to enforcing regulations that protect workers' health and safety from occupational radiation hazards.