A geneticist determines that the order of four genes on a specific chromosome is CABD because the recombination frequencies were 35% for C-D, 24% for A-D, 23% for B-D, and 10% for A-B.

What has the geneticist constructed?

a physical map

a karyotype

a cytogenic map

a linkage map

The geneticist has constructed a linkage map.