prep-sc finishing怎么会表进行时态呢？？

lawrence_yeung

After decreasing steadily in the mid-1990's, the percentage of students in the United States finishing high school or having earned equivalency diplomas increased in the last three years of the decade, up to 86.5 percent in 2000 from 85.9 percent in 1999 and 84.8 percent in 1998.
(A) finishing high school or having earned equivalency diplomas increased in the last three years of the decade, up to 86.5 percent in 2000 from 85.9 percent in 1999 and
(B) finishing high school or earning equivalency diplomas, increasing in the last three years of the decade, rising to 86.5 percent in 2000 from 85.9 percent in 1999 and from
(C) having finished high school or earning an equivalency diploma increased in the last three years of the decade, and rose to 86.5 percent in 2000 from 85.9 percent in 1999 and from
(D) who either finished high school or they earned an equivalency diploma, increasing in the last three years of the decade, rose to 86.5 percent in 2000 from 85.9 percent in 1999 and
(E) who finished high school or earned equivalency diplomas increased in the last three years of the decade, to 86.5 percent in 2000 from 85.9 percent in 1999 and

网上解析：答案是E，前面用decreasing，如果后面还用finishing这样的进行时态就说明这几个动作应该是同时出现的，但应该是前出现decreasing，后面在出现finish和earn这两个动作，所以用过去式求问各位大神，这里的finishing不是只是单纯表示一种状态吗？？就是做modifier，为什么算进行时态？？
btw：纠结很久这个题，觉得还是没有最优答案，求各路大神解析，任何选项都可以，关于finishing时态的最佳，感激不尽！！！

vi.len

RON说过，句子里哪个动作先出现，哪个就发生在前面。decreasing在前面出现修饰percentage。
ABC要直接排除，最重要的是，没有main verb！！
直接排除掉就好啦，不要纠结