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': '10-days rule is related to \nSelect and explain. \nA. Radiation protection in pregnancy, B. Air quality, C. Water quality, D. Sewage disposal', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]