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': 'Most stable radio-isotope among the following – \nSelect and explain. \nA. O –18, B. C – 14, C. P – 32, D. I – 125', 'role': 'user'}, {'content': 'Answer: A \nExplanation: O-16,O-17, O\xa0-18 are stable radioisotopes of oxygen.\nC-12, C-13, are stable radioisotopes of carbon (not C-14).\nP-31, is stable radioisotopes of phosphorus (not P-32).\n1-125 is radioactive form of iodine (not stable).', 'role': 'assistant'}]