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: Pathology
[{'content': 'Antibody against tumor cells - \nSelect and explain. \nA. MHC-I, B. MHC-II, C. Anti viral, D. Differentiated antigen', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]