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: Pathology
[{'content': 'Which of the following blood disease has a racial predilection? \nSelect and explain. \nA. Purpura, B. Hemophilia, C. Polycythemia, D. Thalassemia', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]