The cost of capital is a. the rate of return required by investors in the firm's securities b. the minimum rate of return required on new investments of average risk undertaken by the firm c. approximately 10 percent for most firms d. a and b only The _____ is the discount rate that should be employed to calculate the present value of a proposed investment project's expected cash flow. a. cost of capital b. required rate of return c. hurdle rate d. all of the above