This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Inflammation & Repair, Subject name: Pathology
Which of the following is not an activator of alternate complement system? 
Select and explain. 
A. Factor H, B. IgA, C. Bacteria, D. Immune complex
D: Immune complex
Answer: D: Immune complex 
Explanation: Ans. (d) Immune complexAlternative pathway*. Triggered by microbial surface molecules (e.g., endotoxin, or LPS), complex polysaccharides, cobra venom, and other substances, in the absence of antibody*. IgA can directly activate this pathway