You are the product actuary for company A+ Life. You have developed a five-year decreasing annuity that pays 1,000 per unit at the end of the first year, 500 at the end of the second year, 33331 at the end of the third year, 250 at the end of the fourth year, and 200 at the end of the fith year: Calculate the Macaulay duration for this annuity given an annual effective interest rate of 5%. 2.5>2.5and3.0>3.0and3.5>3.5and4.0>4.0