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: Surgery
Most impoant HLA for organ transplantation and tissue typing - 
Select and explain. 
A. HLA-A, B. HLA-B, C. HLA-C, D. HLA-D
D: HLA-D
Answer: D: HLA-D 
Explanation: Ans. is 'd' i.e., HLA-D