Imagine that a country can produce just two things: goods and services. Assume that over a given time period it could produce any of the following combinations: Units of goods 0 10 20 30 40 50 60 70 80 90 100 Units of services 80 79 77 74 70 65 58 48 35 19 0 a. Draw the country's production possibility curve. b. Assuming that the country is currently producing 40 units of goods and 70 units of services, what is the opportunity cost of producing another 10 units of goods? c. Explain how the figures illustrate the principle of increasing opportunity cost.