What Is the Idea Behind the Income-Contingent Loan Financing Scheme

What is the idea behind the income-contingent loan financing scheme?

A) Grants awarded to many students should be raised in order to improve access to higher education and reduce student debt-loads upon graduation.
B) Tuition should be lowered for all students in order to improve access to higher education and reduce student debt-loads upon graduation.
C) Tuition should be raised somewhat in order to boost the quality of education, but repayment of student loans should be contingent upon graduation.
D) Tuition should be raised somewhat in order to boost the quality of education provided, but repayment of student loans should be geared to the student's income after graduation.
E) Tuition should be raised somewhat in order to boost the quality of education, but in the event of a default, student loans should be forgiven.