This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ear, Subject name: ENT
Most common site for initiation of stapedial otosclerosis is: 
Select and explain. 
A. Fissula ante-fenestram, B. Fossula post-fenestram, C. Footplate of stapes, D. Margins of stapes
A: Fissula ante-fenestram
Answer: A: Fissula ante-fenestram 
Explanation: Most common site for otosclerosis to start is fissula ante-fenestram - an area lying in front of oval window. Other sites listed in the question are also affected but their involvement is less frequent.