Which of the following statements about profit-volume charts is true? a.The slope of the profit line is the same as the slope of the total cost line on the break-even chart. b.Profit-volume charts provide more information than break-even charts. c.The slope of the profit line is the same as the slope of the revenue line on the break-even chart. d.Total profit is actually plotted on the profit-volume chart but must be calculated from information on the break-even chart.