求教一道迷雾一样的语法

lllmmm

According to some economists, the July decrease in unemployment so*******suggests that the gradual improvement in the job market is continuing.
(A) so that it was the lowest in two years
(B) so that it was the lowest two-year rate
(C) to what would be the lowest in two years
(D) to a two-year low level
(E) to the lowest level in two years  
答案是E  请问D为什么不对

小默1108

个人觉得可能是因为没有突出 lowest？

myaska

two-year 在这里有歧义，表示有可能是持续2年低水平，而不是两年内的一个低点

见 http://www.manhattangmat.com/forums/two-year-low-level-is-this-wrong-t1368.html