Flatfish, such as the flounder, are among the fewvertebrates that lack approximate bilateral symmetry (symmetry in whichstructures to the left and right of the body‘s midline are mirror images). Moststriking among the many asymmetries evident in an adult flatfish is eyeplacement: before maturity one eye migrates, so that in an adult flatfish botheyes are on the same side of the head. While in most species with asymmetries virtually all adults share the sameasymmetry, members of the starry flounder species can be either left-eyed (botheyes on the left side of head) or right-eyed. In the waters between theUnited States and Japan, the starry flounder populations vary from about 50percent left-eyed off the United States West Coast, through about 70 percentleft-eyed halfway between the United States and Japan, to nearly 100 percentleft-eyed off the Japanese coast.
According to the passage, starry flounder differfrom most other species of flatfish in that starry flounder
(A) are not basically bilaterally symmetric？
(B) do not become asymmetric until adulthood？
(C) do not all share the same asymmetry？
(D) have both eyes on the same side of the head？
(E) tend to cluster in only certain geographicregions