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: Medicine
[{'content': 'True about MHC: \nSelect and explain. \nA. Transplantation reaction, B. Autoimmune disease, C. Involved in T-cell function, D. All', 'role': 'user'}, {'content': 'Answer: D \nExplanation: A i.e. Transplantation reaction; B i.e. Autommune disease; C i.e. Involved in T -Cell function', 'role': 'assistant'}]