This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Radiotherapy Pa 1, Subject name: Radiology
[{'content': 'The technique employed in radiotherapy to counteract the effect of tumour motion due to breathing is known as \nSelect and explain. \nA. Arc technique, B. Modulation, C. Gating, D. Shunting', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Gating Respiratory gating : It is a technique in radiotherapy in which the radiation is applied during that phase of respiratory cycle in which the tumour is in the best range. This is to prevent unnecessary radiation exposure to normal structures.', 'role': 'assistant'}]