This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Otosclerosis, Subject name: ENT
The part most commonly involved in otosclerosis is: 
Select and explain. 
A. Oval window, B. Round window, C. Tympanic membrane, D. Malleus
A: Oval window
Answer: A: Oval window 
Explanation: (a) Oval window(Ref. Cummings, 6th ed., 2211)Since the most common site of origin of otosclerosis is fissula ante fenestrum, the overgrowth from here comes over the footplate of stapes lying over the oval window. So the part most commonly involved in otosclerosis is oval window.