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: Medicine
[{'content': 'In which of the following conditions splenctomy is not useful? \nSelect and explain. \nA. Herediatary spherocytosis, B. Porphyria, C. Thalassemia, D. Sickle cell disease with large spleen', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]