What are typical sources of ionizing radiation?

• A. Only natural background radiation.
• B. Medical use and industrial use such as diagnostic imaging and soil density measurements.
• C. Only nuclear power plants.
• D. Only radiopharmaceutical therapy.

Answer: (B)

Ionizing radiation comes from a mix of natural background and human-made sources. In everyday practice, medical uses such as diagnostic imaging (X-rays, CT scans) expose patients and health workers to radiation. Industrial applications, like soil density measurements and other gauging techniques, also rely on radioactive sources or radiation-generating equipment. These medical and industrial uses are widespread and familiar to many people, making them representative sources of typical exposure. The other options are too narrow or exclude major common sources (natural background, or broad-based medical and industrial exposure), so this combination best reflects what people are most likely to encounter.