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
Fluctuating recurring variable sensorineural deafness is seen in: 
Select and explain. 
A. Serous otitis media, B. Hemotympanum, C. Perilymphatic fistula, D. Cholesteatoma
C: Perilymphatic fistula
Answer: C: Perilymphatic fistula 
Explanation: (c) Perilymphatic fistula(Ref. Scott Brown, 8th ed., Vol 2; 1085)Serous otitis media can lead to Fluctuating conductive deafness.In hemotympanum and Cholesteatoma the hearing loss is mainly conductive and not fluctuating.