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': "Caplan's syndrome is \nSelect and explain. \nA. Splenomegaly + Neutropenia, B. Rheumatoid Arthritis + Pneumoconiosis, C. Pneumoconiosis + Splenomegaly, D. Pneumoconiosis + Neutropenia", 'role': 'user'}, {'content': "Answer: B \nExplanation: Rheumatoid Arthritis + Pneumoconiosis nodules = Caplan's syndrome.\nNeutropenia +\xa0Splenomegaly + Nodular RA = Felty's syndrome.", 'role': 'assistant'}]