19. Refer to the figure below. P Walnuts A exports S $9 B D $5 gains C from trade D Q 20 40 60 Tons Walnutia is a small country that produces walnuts. 10 years ago, Walnutia did not trade walnuts with other countries and their domestic price was in equilibrium. Later, Walnutia opened their market and started free trade walnuts with the world market. Nowadays, their price reached equilibrium again, but this time, at the world price of the good. Briefly explain how their supplies and demands have shifted and compare the surplus with and without trade. (Hint: What is the Small Economy Assumption? What are the domestic price (Pp) and world price (Pw), and where can you find them in the figure? How much is the domestic demand before free trade? What does area A+B+C represent? What does area A+B+C+D represent? Is trade beneficial for Walnutia's economy?)