This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General Pathology, Subject name: Pathology
[{'content': 'The hypersensitivity reaction involved in the hyperacute rejection of renal transplant is: \nSelect and explain. \nA. Type I, B. Type II, C. Type III, D. Type IV', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Types of graft rejection Type Onset Mechanism Type of Hypersensitivity Hyperacute Immediate Preformed antibodies directed against donor tissue II Acute Days to weeks Mediated by T cells and antibodies that are activated by alloantigens in the graft IV Chronic Months to years T cells that react against graft alloantigens and secrete cytokines, alloantibodies also contribute to chronic rejection. III & IV', 'role': 'assistant'}]