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
Method of prevention of GVHD in bone marrow transplantation is 
Select and explain. 
A. T-cell removal, B. Prior immune suppression, C. Post procedure immune suppression, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Answer- D. All of the abovePrior immunosuppressionT cell depletion from the marrow or stem cellsTreatment after transplant