Based on my knowledge of student loans and their potential impact on future borrowing, the answer is E) defaulting on a student loan.
Defaulting on a student loan can make it very difficult for a borrower to get approved for future loans like a housing/mortgage loan or auto/vehicle loan. Defaulting indicates the borrower failed to make payments on the student loan as required. This looks risky to future lenders.
The other answer choices would not necessarily make it difficult to borrow in the future:
A) Not filing the FAFSA just means potentially missing out on aid, not a negative mark.
B) Work-study programs allow students to earn money for school through a part-time job. This would not affect future borrowing.
C) Borrowing more than required might mean the student takes on more debt, but regular on-time payments would still build credit.
D) Getting a loan cancelled/discharged (forgiven) would actually improve credit by removing the debt.
So of the options, only choice E of defaulting on a previous student loan would likely make it difficult to get approved for major loans like a mortgage or auto loan in the future.