What is the relationship between radiopharmaceuticals, tracers, and radionuclides?

A radionuclide is the radioactive component incorporated into a radiopharmaceutical. The radiopharmaceutical can then be used as a tracer to follow a biological process or show how a substance moves through the body, so the correct choice is “A radionuclide is part of a radiopharmaceutical, which functions as a tracer.”

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