A graph shows Average Cost on the vertical axis and Quantity of Books Sold per Month on the horizontal axis. There are four small U-shaped curves, and one large curve labeled Long-Run Average Cost that intersects the first small curve at a quantity of 1,000 and a cost of $22, the second small curve at a quantity of 20,000 and a cost of $18, the third small curve at a quantity of 40,000 and a cost of $18, and the fourth small curve at a quantity of 80,000 and a cost of $20. The Long-Run Average Cost curve rises sharply after a quantity of 80,000. According to the graph, which level of output represents the minimum efficient scale in bookselling? ANSWER Unselected 1,000 books Unsure I AM UNSURE 20,000 books Unselected 40,000 books