This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Radiology
[{'content': 'X-rays causes radiation damage primarily by their property of \nSelect and explain. \nA. Penetration, B. Radio activity, C. Electromagnetic induction, D. Ionisation', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]