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 pure tone audiogram with a dip at 2000 Hz is characteristic of- 
Select and explain. 
A. Presbyacusis, B. Ototoxicity, C. Otosclerosis, D. Noise induced hearing loss
C: Otosclerosis
Answer: C: Otosclerosis 
Explanation: Dip at 2000 Hz in PTA called as carharts notch is characteristic of otosclerosis.