Verbal分册27题求NN们指教！

w.melhere

27. Obtaining an investment-grade rating will keep the county's future borrowing costs low, protect its already-tattered image, and increase its ability to buy bond insurance.

(A) Obtaining an investment-grade rating will keep the county's future borrowing costs low, protect
(B) To obtain an investment-grade rating will keep the county's future borrowing costs low, and protect
(C) Having obtained an investment-grade rating will, in keeping the county's future borrowing costs low, protect
(D) To obtain an investment-grade rating would keep the county's future borrowing costs low, protecting
(E) Obtaining an investment-grade rating, keeping the county's borrowing costs low, would be protecting

OA是A。

这道题LZ选对了，但看了答案觉得似乎有大文章。答案有些部分也没有看懂，还求NN们指教。

B) The infinitive subject TO OBTAIN suggests that obtaining an investment grade rating is an ovjective in and of itself, not a means to achieve the desired benefits.
这里高亮部分的含义不太理解。在做题时也迷惑了 to do 的选项。 请问到底应该怎么判断呢？

D) The faulty parallelism is confusing; PROTECTING  introduces an adjective phrase describing the subject of the sentence, but this makes INCREASE into a verb with no subject.
这里可以理解protecting 使得这个分句成了一个modifier。但是后面说的increase变成了一个无主语的动词，是因为modifier打断了并列关系么？ 可以帮我分析一下句子结构么？

欢迎大家讨论~  
小女子跪谢！！！

w.melhere

  刚才在群里姐姐帮助下好像理解了B的问题。 to do 表目的故使得句子结构改变，句意改变。
  这样理解对么？


  自己顶一下... 希望能被看到。