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': 'Gram-negative bacteria doesn’t take gram stain because it is made of: \nSelect and explain. \nA. Polysaccharide, B. Lipopolysaccharide, C. Techoic acid, D. None of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: The exact mechanism of gram reaction is not known. The possible reason are :\nGram positive bacteria have a more acidic protoplasm, which account for their retaining the basic primary dye more strongly.\nDye lodine complex is retained in gram positive cells by thick peptide glycan mesh and is readily wash through the very thin peptidoglycan layer of gram – ve cells.', 'role': 'assistant'}]