Graph shows values along the horizontal axis and vertical axis. Coordinates are plotted to indicate two upward-sloping diagonal lines and two downward-sloping diagonal lines. Line 1 is a downward sloping line with point S at 300, 300 and Point U at 200, 400. Line 2 is a downward sloping line with point T at 500, 300. Line 3 is an upward sloping line with Point S at 300, 300 intersecting line 1 at S and also intersecting line 2. Line 4 is an upward sloping line with point T at 500, 300 intersecting Line 2. Use the above graph to answer the following question. Pretend this graph represents the market for books. Which situation would cause the graph to shift from line 1 to line 2? An increase in the price of books A fire that destroys the paper factories A decrease in the price of book-binding glue A celebrity commercial encouraging reading