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
A 30 years woman presents with progressive conductive deafness bilaterally. The most common cause is - 
Select and explain. 
A. Tympanosclerosis, B. Otospongiosis, C. Meniere's disease, D. Bilateral wax in external ears
B: Otospongiosis
Answer: B: Otospongiosis 
Explanation: None