Which of the following are ALARA controls?

• A. Time
• B. Shielding
• C. All of the Above
• D. Distance

Answer: (C)

ALARA controls are the safeguards used to keep radiation exposure as low as reasonably achievable. The three fundamental strategies are reducing time, increasing distance, and using shielding. Reducing time means spending less time near the source, which cuts the cumulative dose. Increasing distance takes advantage of the inverse square law—the dose drops rapidly as you move farther away from the source. Shielding provides a physical barrier (like lead or concrete) that absorbs or blocks radiation before it reaches you. Because all three strategies work together to lower dose, the option that includes all of them is the best choice.