This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteria, Subject name: Microbiology
[{'content': 'The subarachnoid space inflammation of bacterial meningitis, which is caused by a gram-negative bacterium, is induced by which one component of the bacteria? \nSelect and explain. \nA. Matrix protein, B. Lipopolysaccharide (LPS), C. Pili, D. Inner membrane', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B. Lipopolysaccharide (LPS)ENDOTOXINS: are part of the outer cell wall of gram negative bacteria.* Lipopolysaccharides consists of three components:(1) Lipid A(2) Core polysaccharide(3) O polysaccharide* The biological activity of endo toxin is associated with the lipid A portion of LPS.', 'role': 'assistant'}]