This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
[{'content': 'True about immunoglobulins - \nSelect and explain. \nA. IgE has minimum concentration, B. IgG has minimum concentration, C. IgA has minimum concentration, D. IgM has minimum concentration', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Of IgE is typically the least abundant isotype--blood serum IgE levels in a normal individual are only 0.05% of the Ig concentration Ref: Ananthanarayan & Panikers textbook of microbiology 9th edition pf:98', 'role': 'assistant'}]