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': 'Unit of measurement to compare radiation damage \nSelect and explain. \nA. Exposure, B. Absorbed dose, C. Effective dose, D. Equivalent dose', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]