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: Pathology
[{'content': 'Direct Coombs test is positive for: \nSelect and explain. \nA. IgA, B. IgE, C. IgM, D. IgG', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Autoimmune hemolytic anaemia in which the red cell injury is brought about by auto-antibodies reacting with antigens present on red cell membrane.\xa0\nAntiglobulin test (direct Coombs’ test) is employed to detect the antibody on red cell surface.\n\nKey Point:\nDAT (Direct Antiglobulin Test) testing typically involves the use of a polyspecific reagent consisting of IgG and complement C3.\nMohan H. Textbook of pathology. Jaypee Brothers Medical Publishers; 2015. Edition 7. Page 60', 'role': 'assistant'}]