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': 'TRUE about immunoglobulins is: \nSelect and explain. \nA. IgE fixes complements, B. IgM fixes complements, C. IgG is found in minimum concentration, D. IgG is elevated in primary immune response', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Answer is B (IgM fixes complements): IgM and IgG .fix complement the classical pathway', 'role': 'assistant'}]