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': 'Earliest sign of raised ICT is: \nSelect and explain. \nA. Erosion of dorsum sella, B. Copper beaten appearance, C. Silver beaten appearance, D. Displacement of pineal gland', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Erosion of dorsum sella', 'role': 'assistant'}]