This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Plasma Cell Disorders and Multiple myeloma, Subject name: Pathology
[{'content': 'M-spike in multiple myeloma is due to? \nSelect and explain. \nA. IgM, B. IgA, C. IgG, D. IgD', 'role': 'user'}, {'content': 'Answer: C \nExplanation: In Multiple myeloma laboratory analyses reveal increased levels of Igs in the blood and/or light chains (Bence-Jonesproteins) in the urine. The most common monoclonal Ig ("M protein") is IgG (approximately 55% ofpatients), followed by IgA (approximately 25% of cases).', 'role': 'assistant'}]