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: Microbiology
[{'content': 'Antibodies are most responsive to - \nSelect and explain. \nA. Recipients tissue, B. Donor tissue, C. Isografts, D. Autograft', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Donor tissue During graft rejection antibodies are formed against donor tissue.", 'role': 'assistant'}]