This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Haematology, Subject name: Medicine
[{'content': 'Not affected in multiple myeloma - \nSelect and explain. \nA. IgG, B. IgA, C. IgM, D. IgD', 'role': 'user'}, {'content': "Answer: C \nExplanation: Types of monoclonal protein in multiple myeloma include IgG,(55%),IgA(21%), light chain only(22%), others(D,E,non-secretory about 2%).Reference :Davidson's principles & practice of medicine 22nd edition pg no 1046.", 'role': 'assistant'}]