Richard French,53 Years Old,was Diagnosed with Chronic Myelogenous Leukemia

Richard French,53 years old,was diagnosed with chronic myelogenous leukemia.His elder brother Don is HLA-haploidentical and will donate bone marrow.Richard's oncologist has recommended him to a medical center that favors using bone marrow depleted of mature T cells prior to infusion.The most likely rationale for employing the practice of T-cell depletion is that _____.

A) T-cell depletion will remove alloreactive T cells from the donor and prevent the potential for graft-versus-host disease (GVHD)
B) mature T-cell chimerism is required to establish long-term tolerance
C) because Don is HLA-haploidentical and male,there is no risk of alloreactivity toward major or minor histocompatibility antigens
D) because of Don's age,the expected bone marrow harvest is already marginal for successful engraftment,and depletion measures would compromise the yield of stem cells
E) the benefit of using a cocktail of immunosuppressive drugs outweighs the risk of contaminating the bone marrow during T-cell depletion.