This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Brain , Subject name: Anatomy
[{'content': 'Middle ear is separated from cerebrum by \nSelect and explain. \nA. Tegmen tympani, B. Sphenoid bone, C. Jugular wall, D. Carotid wall', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The roof of the tympanic cavity is formed by a thin plate of bone, the tegmen tympani, which separates the cranial and tympanic cavities. imageref- sciencedirect.com', 'role': 'assistant'}]