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': 'Autoantigen is - \nSelect and explain. \nA. Blood group antigen, B. Forssman antigen, C. Both, D. None', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Sequesterd antigen that are not normally found free in ciculation or tissue fluids such as eye lens protien Ref: Ananthanarayan & Panikers textbook of microbiology 9th edition pg:89', 'role': 'assistant'}]