74.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.
(C) because they enhance reproduction or survival, but
(D) because they enhance reproduction or survival, but are
想詢問實戰上C、D的解題方法/觀念
看了Ron及語法筆記的解釋仍然不太明白為何選C會造成ambiguous
感謝各位版上神人釋疑！！

but後面要S+V,but(many biological traits)are

(C)but會有兩種解釋方式,一種是你提的,另一則是跟because後面的子句做轉折,如果讀者還要花時間去思考那句子就不夠concise,補出are可以讓讀者直接對到第一種