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: Unknown
[{'content': 'Which of the following is a Opsonin? \nSelect and explain. \nA. C3a, B. C3b, C. C5a, D. LTC4', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ref. Robbins Pathology. 9th edition. Page. 78\n\xa0\nExamples of opsonins include:\n\nAntibodies:\n\t\nIgG and IgA\n\n\nComponents of the complement system:\n\t\nC3b, C4b, and iC3b\n\n\nMannose Binding Lectin (MBL)\nMembrane Attack Complex (MAC)', 'role': 'assistant'}]