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': 'The following disease without splenomegaly for which splenectomy is effective - \nSelect and explain. \nA. Sickle cell disease, B. Idiopathic thrombocytopenic purpura, C. Aplastic anaemia, D. Thalassemia', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]