Suppose Ceramica produces plates and toilets subject to the following production possibilities frontier: Toilets Plates 500 1,500 600 1,300 700 1,000 800 600 900 100 What is the opportunity cost to Ceramica of increasing the production of toilets from 500 to 700. a) 100 toilets b) 200 plates c) 500 plates d) 1,500 plates