Choice "D" is correct. The profitability index is used for capital rationing. The profitability index is the ratio of the present value of net future cash inflows to the present value of the net initial investment. Ranking and selection of investments is made by listing projects in descending order. Limited capital resources are applied in the order of the index until resources are either exhausted or the investment required by the next project exceeds remaining resources.Choice "b" is incorrect. The net present value method is a technique to screen investments for compliance with capital investment policy or criteria, not a capital rationing method.Choice "a" is incorrect. The internal rate of return method is a technique to screen investments for compliance with capital investment policy or criteria, not a capital rationing method.Choice "c" is incorrect. The return on investment method is a technique to screen investments for compliance with capital investment policy or criteria, not a capital rationing method.