Lucky 13 - if they are learning the course material during class time shouldn't they take the Exam during scholarship hours as well? The SAT doesn't directly affect the GPA of a student nor connected to one specific class. AP is more specific and directly effects AP Credits earned.
SAT Subject Tests measure students’ readiness for college-level work in a certain subject.
AP Tests are intended to measure a student’s mastery of college-level material through an examination that touches on the main points of a year-long AP curriculum.