若是C的話, because it is so genetically similar, 並沒有說什麼東西相似, 照句意來說不完整
我認為D較佳,
In A & B, the use of "due to" is informal.
In E, "because of" should be followed with nouns
In C, ...struggles that limit the spread of this species in "its" native Argentina. "its" refers to "this species."