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: Microbiology
[{'content': "All the following diseases contain abnormal immunoglobulin except: \nSelect and explain. \nA. Multiple myeloma, B. Reactive arthritis, C. Seligman's disease, D. Franklin's disease", 'role': 'user'}, {'content': "Answer: B \nExplanation: Multiple myeloma – Bence Jones proteins\nSeligmann's disease –\xa0Alpha chain\nFranklin's disease –\xa0Gamma chain", 'role': 'assistant'}]