Sentence Correction (SC) | High school students are often encouraged by their parents to

High school students are often encouraged by their parents to study diligently for AP exams,which allow them to skip certain required college courses and save substantially on overall tuition costs.

A. which allow them to skip certain required college courses and save substantially on overall tuition costs
B. which allow the students to skip certain required college courses and save substantially on overall tuition
C. which, if the score is high, allow them to skip certain required college