求助OG VERBAL SC27

sarahcow

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 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 future borrowing costs low, would be protecting

求大侠指教，为什么不可以选B，答案说天哦obtain是an objective in and of itself, not a means to achieve the desired benefits.为什么？不明白OG上的解释？

bobdog159

B选项改变了句子的意思，Obtaining。。。。的意思是获得了XXXX能使得XXXX
而 To obtain。。。。的意思是为了obtainXXXX会XXXXX（纯属个人观点）

还有一点就是 To obtain 缺少一个动作发出的主体（谁obtain）使得句子的表达不及Obtaining有效

kasawoo

B选项改变了句子的意思，Obtaining。。。。的意思是获得了XXXX能使得XXXX
而 To obtain。。。。的意思是为了obtainXXXX会XXXXX（纯属个人观点）

还有一点就是 To obtain 缺少一个动作发出的主体（谁obtain）使得句子的表达不及Obtaining有效

-- by 会员 bobdog159 (2012/3/13 17:53:55)

嗯嗯~楼上说得没错~
to obtain表目标，“is an objective in and of itself”意思是“其本身就是目标”，但实质上题目中它是一个解决问题的手段方法，改变了句意
而且楼上给我启发很大的就是，To obtain 确实少了动作发出的主题lol

kasawoo

我还想问的就是，D选项，OG的解释是：
protecting introduces an adjective phrase describing the subject of the sentence, but this makes increase into a verb with no subject.
为什么protecting令increase没有了主语？