Brazil can produce one unit of sugar cane for one unit of labor and one iPod for eight units of labor, and China can produce one unit of sugar cane for two units of labor and one iPod for four units of labor. What are each country's opportunity costs of producing iPods? Select one: O a. Brazil: 1/8 unit of sugar cane; China: 1/2 unit of sugar cane O b. Brazil: 4 units of sugar cane; China: 2 units of sugar cane O c. Brazil: 1/2 unit of sugar cane; China: 1/2 unit of sugar cane O d. Brazil: 8 units of sugar cane; China: 2 units of sugar cane