Comprehend and explain the development and contemporary relevance of trade theories, including the economic theories of absolute (see Adam Smith), comparative (see David Ricardo) and competitive advantage (see Michael Porter), and apply these theories using relevant diagrams and models.

Country X can produce 100 units of wheat or 60 units of cloth with all its resources. Country Y can produce 80 units of wheat or 60 units of cloth with all its resources. Which statement correctly explains the basis for trade between these countries?

Two nations, Alpha and Beta, can each produce cloth and steel. The table below shows the maximum quantities each nation can produce per year if all resources are devoted to a single good. Which statement correctly applies the principle of comparative advantage to identify which nation should specialise in cloth production?

Two neighbouring countries, Northland and Southland, each allocate 100 hours of labour to produce wheat and textiles. The productivity data is shown. Ceteris paribus, which statement best explains the pattern of trade according to Ricardo's theory of comparative advantage?