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': 'The cell most sensitive to radiotherapy: \nSelect and explain. \nA. Neutrophil, B. Lymphocyte, C. Monocyte, D. Platelet', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Lymphocyte', 'role': 'assistant'}]