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
The angle that tympanic membrane makes with the floor of meatus is 
Select and explain. 
A. 15 o, B. 25 o, C. 45 o, D. 55 o
D: 55 o
Answer: D: 55 o 
Explanation: 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.