Final answer:
Martin does not need to include any interest in income.
Step-by-step explanation:
To calculate the amount of interest that Martin must include in income, we need to determine the taxable portion of the redeemed savings bonds. In this case, Martin redeemed $3,000 in Series I Savings Bonds to pay qualified higher education expenses, which totaled $2,500. Since the qualified expenses are less than or equal to the value of the bonds, Martin does not need to include any interest in income. Therefore, the correct answer is a. $0.