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': 'Which Antibody has highest molecular weight \nSelect and explain. \nA. IgG, B. IgE, C. IgD, D. IgM', 'role': 'user'}, {'content': 'Answer: D \nExplanation: IgM has highest molecular weight.', 'role': 'assistant'}]