This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nephrotic and Nephritic syndrome, Subject name: Medicine
[{'content': 'Which nephritogenic antigen is detected in subepithelial humps of PSGN? \nSelect and explain. \nA. Streptococcal pyrogenic exotoxin B, B. Nephritis associated plasmin receptor, C. M antigen, D. P antigen', 'role': 'user'}, {'content': 'Answer: A \nExplanation: RF: Type II HSR PSGN: Type III HSR', 'role': 'assistant'}]