Final answer:
Interest income is generally obtained from term deposits, which provide a fixed return, unlike earnings from stocks, RESPs, and mutual funds that may include dividends, grants, and capital gains.
Step-by-step explanation:
Interest income typically originates from investments that promise a fixed return over time. Among the options provided, interest income would come from term deposits, which are savings accounts or certificates of deposit that earn interest at a predetermined rate. Different from term deposits, earnings on stocks come from dividends and potential capital gains, RESPs (Registered Education Savings Plans) involve a mix of contributions, government grants, and investment earnings, and profits from the sale of mutual funds are a form of capital gain rather than interest income.