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': 'Most common used rays for radiotherapy – a) X raysb) γ rays c) α raysd) β rays \nSelect and explain. \nA. ab, B. bc, C. ac, D. cd', 'role': 'user'}, {'content': 'Answer: A \nExplanation: "Several different types of radiation are used to treat patients with malignant conditions. The most frequently used \xa0forms of radiation for cancer therapy, however are , high energy X-rays and gamma rays".', 'role': 'assistant'}]