A University Has an Attendance Policy So That Students' Grades

A university has an attendance policy so that students' grades will suffer should they not come to class. This is a policy that:

A) is not backed by legislation but can be enforced by the school.
B) is not backed by legislation so cannot be enforced by the school legally.
C) is backed by legislation so is independent of the school's institutional policy.
D) is not a law but is supported by the ADA and American Civil Liberties Union.