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
Whisper is 
Select and explain. 
A. 10 db, B. 20 - 30 db, C. 30 - 50 db, D. 60 db
B: 20 - 30 db
Answer: B: 20 - 30 db 
Explanation: None