Read the excerpt from a student’s argumentative essay.

students at glenmore high demand an increase in the number of advanced placement classes. in order to compete with other college-bound students, we must have access to more rigorous courses. i mean, if we can’t show that we took tough courses, colleges will turn us down.

how can the final sentence best be revised for this argument?
a tough work is the key to proving to college admissions that we’ve got what they want.
b we need tougher courses on our transcripts, or else nobody’s going to notice us.
c without proof of challenging courses, colleges might disregard our transcripts.
d challenging courses separate college-bound students from the rest of the pack