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
Carhart's notch is seen in 
Select and explain. 
A. Otosclerosis, B. Acoustic neuroma, C. Meneir's disease, D. CSOM
A: Otosclerosis
Answer: A: Otosclerosis 
Explanation: i.e. (Otosclerosis): (99-Dhingra 5th)* Carhart's notch - maximum at 2000 Hz or 2KHZ carharts notch disappears after successful stapedectomy in OTOSCLEROSIS* Schwartze sign - flamingo-pink bluish tympanic membrane due to hyperaemia of the promontory and affords good evidence that the otosclerotic process is an active phase in OTOSCLEROSISOTOSCLEROSIS (otospongiosis)- Commonest site -fissula ante fenestram**- Painless and progressive bilateral conductive deafness**- Paracusis willisii (hears better in noisy than quite surroundings)**- Tinnitus, vertigo, monotonous speech**