How is the majority of oxygen transported in the blood?

A. major histocompatibility complex: MHC (human leukocyte antigen, HLA) matching is critical because disparities trigger strong T-cell–mediated rejection responses.
B. antibody response: the recipient’s antibody response intensity matters clinically, but you don’t “match” antibody responses between donor and recipient; rather you try to match MHC and blood type.
C. blood type: blood type mismatches can cause hyperacute rejection and are important to consider, but MHC/HLA matching is the key determinant of long-term rejection risk.
D. sex and age: sex and age are not major determinants of graft compatibility; they are not the primary matching criteria used to reduce rejection risk.

A. Maintaining blood glucose concentration: Incorrect (this is a liver function) -the liver stores glycogen and performs gluconeogenesis to regulate blood glucose.
B. Secretion of bile: Incorrect (this is a liver function) -the liver synthesizes and secretes bile.
C. Formation of urea: Incorrect (this is a liver function) -the liver converts ammonia to urea (urea cycle).
D. Secretion of insulin: insulin is produced and secreted by the pancreatic β-cells, not the liver, so this is not a liver function.