Male bowerbirds construct elaborately decorated nests, or bowers. Basing their judgment on the fact that different local populations of bowerbirds of the same species build bowers that exhibit different building and decorative styles, researchers have concluded that the bowerbirds’ building styles are a culturally acquired, rather than a genetically transmitted, trait. Which of the following, if true, would most strengthen the conclusion drawn by the researchers?

 (A) There are more common characteristics than there are differences among the bower-building styles of the local bowerbird population that has been studied most extensively

(B) Young male bowerbirds are inept at bower-building and apparently spend years watching their elders before becoming accomplished in the local bower style.

(C) The bowers of one species of bowerbird lack the towers and ornamentation characteristic of the bowers of most other species of bowerbird.

(D) Bowerbirds are found only in New Guinea and Australia, where local populations of the birds apparently seldom have contact with one another.

(E) It is well known that the song dialects of some songbirds are learned rather than transmitted genetically.

答案是B，明白。但是A为什么不对？A里的local bowerbird population之的是同一species的鸟还是不同species的阿？

先谢过大家拉~~

researchers have concluded that the bowerbirds’ building styles are a culturally acquired, rather than a genetically transmitted, trait

关键在highlighted的这句话上，要说明是后天习得的，不是遗传的。A并没有排除可能是遗传的。B最直接啦～