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
[{'content': 'Principles used in Radio Therapy is: \nSelect and explain. \nA. Infrared rays, B. Ionizing molecules, C. Charring of nucleoprotein, D. Ultrasonic effect', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. Ionizing molecules', 'role': 'assistant'}]