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': 'Bitewing radiographs are taken to look for: \nSelect and explain. \nA. Narrowing of periodontal space, B. Proximal caries, C. Resorption of root, D. Internal resorption', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]