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
All of the following modalities can be used for in-situ ablation of liver secondaries, except – 
Select and explain. 
A. Ultrasonic waves, B. Cryotherapy, C. Alcohol, D. Radio frequency
A: Ultrasonic waves
Answer: A: Ultrasonic waves 
Explanation: Treatment modalities for liver secondaries 

Liver transplant (in patients with single lesion < 5 cm or three or fewer, lesions < 3 cm)
Hepatic artery embolization & chemotherapy (chemoembolization)
Intralesional in situ ablation via ultrasound-guided

         Percutaneous ethanol (alcohol) injection
         Cryotherapy
         Radiofrequency ablation
         Microwave coagulation therapy