Final answer:
State or local regulatory agencies are primarily responsible for enforcing food safety in restaurants, working in conjunction with FDA guidelines.
Step-by-step explanation:
The agency responsible for enforcing food safety in a restaurant is typically a State or local regulatory agency. These agencies work collaboratively with the Food and Drug Administration (FDA) to ensure that restaurants adhere to hygiene and food safety standards to prevent foodborne illnesses. While the FDA sets the regulations and standards for food safety, the actual enforcement within restaurant environments is usually handled at the state or local level, where inspectors conduct routine checks for compliance.