D. Only as much as you need to pay college-related expenses.
When taking out a Direct Stafford Loan for college, it's important to only borrow what you actually need to cover your educational expenses, such as tuition, room and board, textbooks, and other related costs. It's not wise to borrow more than you need just because you can, as this will result in more debt and interest to pay off in the long run. It's also important to remember that student loans must be repaid, so it's important to be responsible and thoughtful when borrowing money for your education.