Choose an electromagnetic wave by matching its properties to the task. Medical imaging needs useful transmission and absorption differences; treatment needs energy deposition in target tissue. Use exposure data to judge risk, and explain a named property rather than simply listing a use. Detailed suitability explanations are Higher tier. Example: Explain why “all EM waves are equally dangerous” is inadequate. Hazards depend on wave type, dose and the exposed tissue. Give a reason. Compare cases.