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: Medicine
[{'content': 'The following group of tests should be done to optimise graft uptake in bone marrow transplant: \nSelect and explain. \nA. Blood grouping, B. HLA matching, C. Culture for infection, D. All of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Most prospective donors are initially typed for HLA-A and HLA-B loci. Donors identified as potential HLA-A and HLA-B matches are then asked to donate a specimen for DR- loci typing. When a donor is identified as a potential HLA-A and HLA-B and a DR match for a given recipient he is checked for transmissible infectious diseases such as Cytomeggalovirus (CMV) etc. Ref: Hematopoietic Stem Cell Transplantation By Michael R. Bishop, Page 86', 'role': 'assistant'}]