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
Hearing loss of 65dB, what is the grade of deafness? 
Select and explain. 
A. Mild, B. Moderate, C. Severe, D. Moderately severe
D: Moderately severe
Answer: D: Moderately severe 
Explanation: WHO classification of the degree of hearing lossThe degree of impairment Hearing threshold in the better earNot significant 0 - 25 dBMild deafness26 - 40 dBModerate deafness41 - 55 dBModerately severe deafness56 - 70 dBSevere deafness 71 - 90 dBProfound deafnessAbove 91 dB Ref: PL Dhingra, Diseases of Ear, Nose & Throat, 7th edition, pg no. 40