Human HLA genes (equivalent to MHC genes in mice) have many alleles, and no two individuals have identical alleles at all gene loci. Which of the following are consequences of this genetic diversity?

A.	Maximizes the kinds of pathogens that can be recognized and eliminated by an immune resonse within a population
B.	Transplanted organs can be rejected
C.	Females mice prefer to mate with males having different alleles at MHC gene loci
D.	All of the above