<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:Two weeks after undergoing allogeneic stem cell transplant for multiple myeloma, a 55-year-old man develops a severely pruritic rash, abdominal cramps, and profuse diarrhea. He appears lethargic. Physical examination shows yellow sclerae. There is a generalized maculopapular rash on his face, trunk, and lower extremities, and desquamation of both soles. His serum alanine aminotransferase is 115 UL, serum aspartate aminotransferase is 97 UL, and serum total bilirubin is 2.7 mgdL. Which of the following is the most likely underlying cause of this patients condition?? A: Donor T cells in the graft, B: Newly formed anti-HLA antibodies, C: Proliferating transplanted B cells, D: Activated recipient T cells, E: Preformed cytotoxic anti-HLA antibodies,  <response>: Based on the description of rash, abdominal cramps, diarrhea, jaundice, and elevated liver enzymes shortly after allogeneic stem cell transplant, the most likely diagnosis is acute graft-versus-host disease GVHD. The timing and symptoms are classic for acute GVHD, which is caused by donor T cells attacking the recipients tissues.A: Donor T cells in the graft 