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': 'Atomic number of Tungsten is \nSelect and explain. \nA. 74, B. 53, C. 63, D. 64', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Tungsten -74\nIodine - 53', 'role': 'assistant'}]