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: Radiology
USG wave travel in the human body at the rate of – 
Select and explain. 
A. 1500 m/s, B. 2500 m/s, C. 3500 m/s, D. None
A: 1500 m/s
Answer: A: 1500 m/s 
Explanation: Speed of sound wave in body is 1540 m/s.