In our notes, we learned about NPV profile graphs. These graphs plot the NPV on the vertical axis and the cost of capital on the horizontal axis. Which of the following correctly represents the vertical axis and the horizontal axis on an NPV profile graph?

a. NPV on the vertical axis and cost of capital on the horizontal axis
b. Return on investment on the vertical axis and cost of capital on the horizontal axis
c. Cost of capital on the vertical axis and NPV on the horizontal axis
d. Return on investment on the vertical axis and NPV on the horizontal axis