[讨论]prep1-7

7.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

答案A，题目很简单没什么好说的。

我想问的是D和E中均把will改成would，因为GMAT的错误选项至少有2个错。在判断不出可能性大还是小的时候，我们是不是可以这种will和would互换的做法当成是使effictiness错呢？