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: Ophthalmology
[{'content': 'Tumours arising from all of thefollowing structures can induce papilloedema except: \nSelect and explain. \nA. Medulla oblongata, B. Cerebrum, C. Olfactory groove, D. Orbital surface of frontal lobe', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. Medulla oblongata', 'role': 'assistant'}]