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
Moderately severe hearing loss: 
Select and explain. 
A. 30-40 dB, B. 41-60 dB, C. 56-70 dB, D. 71-90 dB
C: 56-70 dB
Answer: C: 56-70 dB 
Explanation: Ans. (c) 56-70 dBRef. Dhingra's ENT 6th ed./38 WHO classification for hearing loss:0-25 dBNormal hearing26-40 dBMild hearing loss41-55 dBModerate hearing loss56-70 dBModerately severe hearing loss71-90 dBSevere hearing loss> 90 dBProfound hearing loss