A Major Distinction of Genome-Wide Association (GWA)studies,compared to the More

A major distinction of genome-wide association (GWA) studies,compared to the more traditional approaches of empiric risk,heritability,adoptee and twin studies,is that

A) GWA studies pepper the entire genome with markers,so that even genes that would not be expected to contribute to a phenotype can be discovered.
B) GWA studies actually sequence entire genomes.
C) GWA studies can be performed on healthy individuals.
D) GWA studies consider already-known traits.