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': 'Curie is unit of: \nSelect and explain. \nA. Radiation exposure, B. Radiation absorption, C. Radioactivity, D. All of the above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: C i.e. Radioactivity', 'role': 'assistant'}]