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
Frequency of sound waves used for transabdominal ultrasonography is 
Select and explain. 
A. 2.5-3.5 MHz, B. 3.5-5.0 MHz, C. 5.0-7.5 MHz, D. 7.5-10 MHz
B: 3.5-5.0 MHz
Answer: B: 3.5-5.0 MHz 
Explanation: Ans. 3.5-5.0 MHz