Q29:

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.

1. year toward the cost of higher education, previously paying $7 per year
2. year toward the cost of higher education, for which was previously paid $7 per year
3. year, compared to the previously $7 per year, toward the cost of higher education
4. year toward the cost of higher education, instead of the $7 per year required previously
5. year as opposed to the $7 per year required previously for the cost of higher education

The answer is D, what is wrong with the B?

 Thx