A Canadian equity index fund would be the most tax-efficient option for Xerxes. A Canadian equity index fund is a type of mutual fund that invests in a portfolio of Canadian stocks that track a specific market index, such as the S&P/TSX Composite Index. A Canadian equity index fund would be tax-efficient for Xerxes because it would generate mostly capital gains and eligible dividends, which are taxed at lower rates than interest income or foreign dividends. A Canadian equity index fund would also have low turnover and minimal distributions, which would defer taxes until Xerxes sells his units. The other options are less tax-efficient than a Canadian equity index fund. A target date fund is a type of mutual fund that adjusts its asset allocation over time based on a predetermined retirement date. A target date fund would be less tax-efficient than a Canadian equity index fund because it would have higher turnover and more distributions, which would trigger taxes every year. A target date fund would also invest in a mix of asset classes, such as bonds and foreign equities, which would generate interest income and foreign dividends that are taxed at higher rates than capital gains and eligible dividends. A bond fund is a type of mutual fund that invests in a portfolio of fixed-income securities, such as government bonds, corporate bonds, and mortgage-backed securities. A bond fund would be less tax-efficient than a Canadian equity index fund because it would generate mostly interest income, which is taxed at the highest rate among different types of investment income. A bond fund would also have regular distributions, which would trigger taxes every year. An asset allocation fund is a type of mutual fund that invests in a portfolio of other mutual funds that cover different asset classes, such as stocks, bonds, and cash equivalents. An asset allocation fund would be less tax-efficient than a Canadian equity index fund because it would have higher fees and more distributions, which would reduce the net returns and trigger taxes every year. An asset allocation fund would also invest in a mix of asset classes, some of which would generate interest income and foreign dividends that are taxed at higher rates than capital gains and eligible dividends. References: [Canadian Equity Index Funds], [Tax-Efficient Investing], [Target Date Funds], [Bond Funds], [Asset Allocation Funds]