a) The plan with the highest total amount paid is the Direct Unsubsidized Loan of $19,000 because, in addition to the interest, the principal amount is higher than the Direct Subsidized Loan.
b) The repayment period for the Direct Unsubsidized Loan is 10 years after graduation if the Standard Repayment Plan is chosen.
Subsidized Loans are student loans subsidized by the Federal Government, especially with respect to the interest payment.
Subsidized Loans do not accrue interest during school at least half-time or during deferment periods. They are available for undergraduate and graduate students in financial need.
Unsubsidized Loans are federal student loans for both undergraduate and graduate students that are not based on financial need. They accumulate interest during school if the student does not elect to make monthly interest payments.
Learn more about subsidized and unsubsidized loans at https://brainly.com/question/2651923