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': 'Radiosensitivity of tumour depends on: \nSelect and explain. \nA. Histology, B. Blood supply, C. Nucleus atypia, D. Number of cells', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. Histology', 'role': 'assistant'}]