Which entity routinely samples air, water, and food supplies for radionuclides?

The correct answer highlights that all the listed entities play a role in monitoring radionuclides within air, water, and food supplies. The FDA (Food and Drug Administration) is responsible for ensuring the safety and security of food products, which includes monitoring for radioactive contaminants. The CDC (Centers for Disease Control and Prevention) focuses on protecting public health and safety, thereby engaging in surveillance and response to biological and chemical hazards, including the potential effects of radionuclides on health. The NRC (Nuclear Regulatory Commission) oversees the use of nuclear materials and ensures safety regulations are met, which includes monitoring the impact of radionuclide exposure on the environment and public health.

This collaborative approach among these agencies ensures comprehensive monitoring and regulation, addressing various aspects of public safety regarding radiation exposure. Hence, the ability of all three entities to conduct sampling and their roles in health and safety justify the correctness of the answer.