Assume that for the entire business sector of a private closed economy there is $0 worth of investment projects that will yield an expected rate of return of 25 percent or more. But there are $15 worth of investments that will yield an expected rate of return of 20-25 percent; another $15 with an expected rate of return of 15-20 percent; and similarly an additional $15 of investment projects in each successive rate of return range down to and including the 0-5 percent range. Which of the lines on the above diagram represents these data?