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': 'Maximum permissible radiation dose in pregnancy is – \nSelect and explain. \nA. 0.5 rad, B. 1.0 rad, C. 1.5 rad, D. 2 rad', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Maximum permissible dose in pregnancy is 5 mSv (0.5 rem).\xa0\n\nRem = Rad x Quality factor.\n\nMain radiation exposure during pregnancy can be by X-rays (radiography or CT), and the quality factor of X-rays is 1.\xa0\nThat means Rem = Rad.\nTherefore, the maximum permissible dose in pregnancy is 0.5 rem or 0.5 rad.', 'role': 'assistant'}]