This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: general microbiology, Subject name: Microbiology
[{'content': 'The difference between Gram + ve and Gram -ve organism is that Gram+ve org. contains - \nSelect and explain. \nA. Teichoic acid, B. Muramic acid, C. N-acetyl neuraminin acid, D. Aromatic amino acids', 'role': 'user'}, {'content': "Answer: A \nExplanation: Gram-Positive Gram-Negative Thickness Thicker Thinner Variety of AA Few several Aromatic acid and sulfur-containing amino acids absent present LPS absent or scant present Teichoic acid present absent Ref :Ananthanarayan & paniker's Textbook of Microbiology 9th edition pg no 16 Table 2.2 Comparison of cell walls of Gram-Positive & Gram-Negative", 'role': 'assistant'}]