The Investments Fund sells Class A shares with a front- end load of 6% and an MER of 1% annually, and Class B shares with an MER of 1.5% annually as well as back-end load fees that start at 5% and fall by 1% for each full year the investor holds the portfolio (until the fifth year). Assume the portfolio rate of return before operating expenses is 11% annually. If you plan to sell the fund after 4 years, are Class A or Class B shares the better choice for you? What if you plan to sell after 15 years?