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: Social & Preventive Medicine
Prolonged exposure to noise levels greater than the following can impair hearing permanently ? 
Select and explain. 
A. 40 decibels, B. 85 decibels, C. 100 decibels, D. 140 decibels
C: 100 decibels
Answer: C: 100 decibels 
Explanation: Ans. is 'c' i.e., 100 decibels