(Scenario: Sugar Trade in Birdonia) In autarky, suppose that equilibrium sugar price is $100 per ton in Birdonia, a small agricultural nation. Now, suppose Birdonia engages in free trade with the rest of the world. The world price of sugar is $125 per ton. What action must the government of Birdonia take to ensure that Birdonians do not import sugar at the world price of $125?