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': 'ABO antibodies are \nSelect and explain. \nA. IgG, B. IgA, C. IgM, D. IgD', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Antibody of ABO, Rh system is IgM.', 'role': 'assistant'}]