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 of the following is/are- \nSelect and explain. \nA. IgA crosses placenta, B. Half life of IgG is 23 days, C. IgD is heat stable, D. IgE has highest carbohydrate content', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Half life of IgG is approximately 23days Ref: Ananthanarayan & Panikers textbook of microbiology 9th edition pf:96', 'role': 'assistant'}]