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': 'True about immunoglobulins- \nSelect and explain. \nA. IgE has maximum serum concentration, B. IgG has maximum serum concentration, C. IgA has minimum serum concentration, D. IgM has minimum serum concentration', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]