请教prep-74

Arabesque

74.
                (28503-!-item-!-188;#058&003635)

 

Paleontologist Stephen Jay Gould has argued that many biological traits are not the products of natural selection, favored due to their enhancement of reproduction or survival, but that they are simply random by-products of other evolutionary developments.

 

(A) due to their enhancement of reproduction or survival, but that they are

(B) due to the reproduction or survival they enhance, but they are

(C) because they enhance reproduction or survival, but

(D) because they enhance reproduction or survival, but are

(E) because of enhancing reproduction or survival, but are

答案是D 但是not...but的在这句话里的应用前后明显不平行啊

ktj

同问!

另,favored做什么成分?