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
Auditory fatigue occurs at------Hz – 
Select and explain. 
A. 2000, B. 3000, C. 4000, D. 8000
C: 4000
Answer: C: 4000 
Explanation: None