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
[{'content': 'Most common site for the initiation of otosclerosis is - \nSelect and explain. \nA. Foot plate of stapes, B. Margins of stapes, C. Fissula ante fenestram, D. Fissula post fenestram', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Most common type of otosclerosis – Stapedial otosclerosis\nMost common site of otosclerosis – Fissula ante fenestram (i.e. just in front of oval window)\nMost common site for stapedial otosclerosis – Fissula ante fenestram (i.e. just in front of oval window)\nMost common site for cochlear otosclerosis – Round window\n\nRef. Dhingra 5/e, p 97-98, 6/e, p 86-87', 'role': 'assistant'}]