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 pa 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: Oval window