This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
[{'content': 'Which pa of bacteria is most antigenic - \nSelect and explain. \nA. Proetin coat, B. Lipopolysaccharide, C. Nucleic acid, D. Lipids', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Antigens are usually proteins and polysaccharides, and less frequently, lipids. This includes pas (coats, capsules, cell walls, flagella, fimbrae, and toxins) of bacteria, viruses, and other microorganisms. Lipids and nucleic acids are antigenic only when combined with proteins and polysaccharides. Ref: Ananthanarayan & Panikers textbook of microbiology 9th edition pg:88', 'role': 'assistant'}]