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': 'A thin radiolucent tine which follows the root outline on X-rays is \nSelect and explain. \nA. Lamina dura, B. Periodontal ligament, C. Nutrient canal, D. Pulp', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]