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
The effective diameter of the tympanic membrane: 
Select and explain. 
A. 25 mm2, B. 30 mm2, C. 40 mm2, D. 45 mm2
D: 45 mm2
Answer: D: 45 mm2 
Explanation: Area of tympanic membrane is 90 mm2.Effective area is 55 mrn2(approximately 2/3 of the total area).Significance of large area of tympanic membrane - The area of tympanic is much larger than area of stapes footplate, which helps in conveing sound of greater amplitude but lesser force to that of lesser amplitude and great force.