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
10-days rule is related to 
Select and explain. 
A. Radiation protection in pregnancy, B. Air quality, C. Water quality, D. Sewage disposal
A: Radiation protection in pregnancy
Answer: A: Radiation protection in pregnancy 
Explanation: None