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': 'Contrast used in CT – \nSelect and explain. \nA. Gadolinium, B. Technitium, C. Iodine, D. Chromium', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Iodinated\xa0contrasts are the most commonly used radiocontrast media in radiography and CT.', 'role': 'assistant'}]