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: ENT
[{'content': 'Anterior wall of tympanic cavity contains: \nSelect and explain. \nA. Promontry, B. Bony pa of pharyngotympanic tube, C. Processus cochleariformis, D. Tensor tympani muscle', 'role': 'user'}, {'content': 'Answer: D \nExplanation: The anterior wall has a thin plate of bone which separates the cavity from internal carotid. It also has two openings - the lower one for Eustachian tube and the upper one for the canal of tensor tympani muscle.', 'role': 'assistant'}]