The answer that you should tell Harry is that he should hold profitable investments as long as possible. A capital gain is the difference between the selling price and the purchase price of an asset when the selling price is higher than the purchase price. A capital gain is subject to tax only when it is realized, meaning that the asset is sold or disposed of. Therefore, one way to defer paying tax on capital gains is to hold profitable investments as long as possible and delay selling them until a future year. This allows the investor to postpone paying tax on the capital gain and benefit from the compounding effect of the investment returns. Therefore, option A is correct regarding how to defer paying taxes on capital gains. The other options are not correct or effective ways to defer paying taxes on capital gains. Option B is false because investing in mutual funds just before the dividend paying date does not defer paying taxes on capital gains; rather, it increases the taxable income of the investor by adding dividend income, which may be subject to a gross-up and a tax credit depending on the type of dividend. Option C is false because buying and selling investments actively does not defer paying taxes on capital gains; rather, it triggers more taxable events and increases the transaction costs of investing. Option D is false because holding unprofitable investments as long as possible does not defer paying taxes on capital gains; rather, it reduces the potential return of the portfolio and prevents the investor from using capital losses to offset capital gains from other sources. References: [Capital Gains Tax in Canada | Wealthsimple], [Capital Gains Tax: What It Is and How It Works in Canada], [Capital Gains Tax | GetSmarterAboutMoney.ca]