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': 'All the following will appear caries in an X-ray except \nSelect and explain. \nA. Acrylic resin, B. Calcium hydroxide, C. ZOE, D. Composite', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]