This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Head and neck, Subject name: Anatomy
[{'content': 'The angle that tympanic membrane makes with the floor of meatus is \nSelect and explain. \nA. 15 o, B. 25 o, C. 45 o, D. 55 o', 'role': 'user'}, {'content': "Answer: D \nExplanation: Tympanic membrane is placed obliquely at an angle of 55 degrees with the floor of the meatus. Ref : B D Chaurasia's Human Anatomy , seventh edition , volume 3 , pg. no., 285.", 'role': 'assistant'}]