求教关于V+ing的问题

sunangel1749

1. Most of Portugal’s 250,000 university students boycotted classes in a one-day strike to
protest a law that requires them to contribute $330 a year toward the cost of higher
education, previously paying $7 per year.
A. year toward the cost of higher education, previously paying $7 per year
B. year toward the cost of higher education, for which was previously paid $7 per
year
C. year, compared to the previously $7 per year, toward the cost of higher education
D. year toward the cost of higher education, instead of the $7 per year required
previously
E. year as opposed to the $7 per year required previously for the cost of higher

这题的答案是D，我看解释说A错在paying修饰到education错误。请问SVO, V-ING 分词修饰的是就近的O吗？不能是students paying吗？
求指教！