[求助]大全上没有的一道题，我查了，确实没有！！

chenyuelong

Most of Portugal's 250,000 university students boycotted classes in a one-day strick 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, , toward the compared to the previously $7 per yearcost 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 education

请问B项错在哪里？

chenyuelong

B ,还原成 “，was previously paid for $7 per year for education ”，确实没主语
which 指education没错的吧
请指正

venus2elva

GWD解析说是B的定语从句“没有主语”，但我觉得which不是应该充当了主语么，应该是错在了which就近指代了education而不是cost.
请指正。

venus2elva

是选D吗？

对于介词+which的问题我纠结万年了，不敢乱说。