This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Anatomy
[{'content': 'All of the following modalities can be used for in situ ablation of liver secondaries , except \nSelect and explain. \nA. Ultrasonic waves, B. Cryotherapy, C. Alcohol, D. Radio-frequency', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ultra sonic waves are not described as a method of local Ablative therapy for liver secondaries Local ablative therapy for liver secondaries Crypotherapy Radio-frequency or microwave ablation Ethanol, acetic acid, chemotherapy, hot saline Ref: Sabiston 20th edition Pgno :1464-1465', 'role': 'assistant'}]