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': 'Cervical burnout is a phenomenon caused by \nSelect and explain. \nA. Decreased X-ray absorption in the cervical region of teeth with proximal caries, B. Decreased X-ray absorption in the cervical region of normal teeth, C. Decreased X-ray absorption in the cervical region of teeth with root caries, D. Decreased X-ray absorption in the cervical region of hypoplastic teeth', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]