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: Medicine
[{'content': 'Pseudothrombocytopenia is due to platelet agglutination antibodies when the calcium content is decreased by blood EDTA. The antibody to cause this effect is mainly: \nSelect and explain. \nA. IgG, B. IgA, C. IgM, D. IgD', 'role': 'user'}, {'content': 'Answer: A \nExplanation: IgG is the most common antibody to cause platelet agglutination and cause pseudothrombocytopenia. Ref: Harrison Edition - 18, Page - 965', 'role': 'assistant'}]