Which of the following federal agencies is responsible for setting and enforcing regulations to assure safe and healthy working conditions?

The Occupational Safety and Health Administration, commonly known as OSHA, is the federal agency responsible for ensuring safe and healthy working conditions by setting and enforcing regulations related to workplace safety. OSHA develops requirements that employers must follow to prevent workplace hazards and protect employees from injury and illness.

OSHA's role is crucial in promoting a safe working environment, as it establishes guidelines for a wide range of industries and conducts inspections to ensure compliance. This enforcement capability allows OSHA to address issues such as exposure to harmful substances, prevention of accidents, and ensuring adequate safety training for workers.

In contrast, while other agencies like the CDC and NIOSH also play important roles related to public health and safety, they do not focus specifically on workplace safety regulations and enforcement. The CDC primarily provides information and guidance on public health issues, while NIOSH conducts research and makes recommendations for the prevention of work-related illnesses and injuries. The FDA regulates food and drug safety but does not have a mandate over general working conditions. Thus, OSHA is the correct choice as it directly addresses the establishment and enforcement of workplace safety standards.