The production possibilities curve below shows the hypothetical relationship between the production of guns (national defense) and butter (social goods) in an economy. Combination Guns Butter A 0 8 B 20 6 C 60 4 D 80 2 E 100 0 Your response should be a number ONLY. 1. What is the marginal opportunity cost of moving from 2 to 4 units of butter? Guns. 2. What is the total opportunity cost of producing the four (4) unit of butter? Guns 3. What is the marginal opportunity cost of moving from 4 to 6 units of of butter? Guns 4. What is the total opportunity cost of producing six (6) unit of butter? Guns