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: Social & Preventive Medicine
[{'content': 'Radiation protection shields are made up of- \nSelect and explain. \nA. Copper, B. Silver, C. Lead, D. Tin', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Lead o Effective preventive measure for high risk group e.g., X-ray technician is to use lead shields and lead rubber aprons.", 'role': 'assistant'}]