Paper (millions of tons) 16 19 20 Steel (millions of tons) Refer to Figure 2-5. If the firms in the economy are currently producing at point X, what is the opportunity cost of moving to point W? O not producing 19 million tons of steel / extra 4 million tons of paper O not producing 9 million tons of paper / extra 16 million tons of steel O not producing 3 million tons of steel / extra 5 million tons of paper O not producing 5 million tons of paper / extra 3 million tons of steel