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 most radiosensitive cells in the body are \nSelect and explain. \nA. Endothelial cells, B. Epithelial cells, C. Red blood cells, D. White blood cells', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]