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
No prior immune suppression is helpful in which type of graft rejection ? 
Select and explain. 
A. Acute rejection, B. Hyperacute rejection, C. Chronic rejection, D. None of the above
B: Hyperacute rejection
Answer: B: Hyperacute rejection 
Explanation: Answer- B. Hyperacute rejectionHyperacute rejection is caused by ABO incompatibility and preformed cytotoxic antibodies against donor HLA antigens.