A set of line and bar and pie graphs to be used to find the one variable graphs. Graph A: Y-axis shows sales in millions of automobiles from 0 to 7.5 and x-axis shows years from 2007 to 2011. The line follows in the following approximate coordinates: (2007, 7.2), (2008, 7.8), (2009, 7), (2010, 7), (2011, 6.7). Graph B: y-axis shows share of the U.S. automobile market from 0 to 70 percent and x-axis shows different firms. The data are as follows: Big three: 58.1 percent; Japanese firms: 30.9 percent; European firms: 7.3 percent; Korean firms: 3.7 percent. Graph C: A pie chart showing the following data: Big three: 58.1 percent; Japanese firms: 30.9 percent; European firms: 7.3 percent; Korean firms: 7.3 percent. Refer to Graphs A, B, and C. Which graphs are one-variable graphs?