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
Pseudothrombocytopenia is due to platelet agglutination antibodies when the calcium content is decreased by blood EDTA. The antibody to cause this effect is mainly: 
Select and explain. 
A. IgG, B. IgA, C. IgM, D. IgD
A: IgG
Answer: A: IgG 
Explanation: IgG is the most common antibody to cause platelet agglutination and cause pseudothrombocytopenia. Ref: Harrison Edition - 18, Page - 965