Jill Chew is a retired nurse and wishes to choose the best of four immediate retirement annuities available to her. In each case, in exchange for paying a premium today (i.e., some single amount today), she will receive equal annual end-of-year cash flows for a specified number of years. She considers the annuities to be equally risky and is not concerned about their differing lives. Her decision will be based solely on the rate of return she will earn on each annuity. The key terms of each of the four annuities are shown in the following table. Premium Annual Life Annuity Paid Today Cash Flow (years) $30,000 $3,100 20 25,000 3,900 40,000 4,200 15 35,000 4,000 a. Calculate to the annual rate of return on each of the four annuities Jill is considering. b. Given Jill's stated decision criterion, which annuity would you recommend