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': 'All are feature of radiaiton except \nSelect and explain. \nA. Biological, B. Photographic, C. Fluorescent, D. Non penetrating', 'role': 'user'}, {'content': 'Answer: D \nExplanation: D i.e. Non penetrating There is nothing to explain as radiation may be penetrating also. (Example gamma rays)', 'role': 'assistant'}]