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
Auditory fatigue is at ? 
Select and explain. 
A. 90 dB 4000 Hz, B. 110 dB 4000 Hz, C. 130 dB 4000 Hz, D. 150 db 4000 Hz
A: 90 dB 4000 Hz
Answer: A: 90 dB 4000 Hz 
Explanation: Ans. is 'a' i.e., 90 dB 4000 Hz