JC Inc. must install a new air-conditioning unit in its main plant. It is evaluating two different models: A and B; both are expected to last six years and are equally efficient. The cash flows (in millions) are listed below. JC's WACC is 8%. What unit would you recommend? If WACC changes to 10%, which unit would you recommend? t = 0 1 2 3 4 5 6 A - 150 - 125 - 125 -175 - 175 -200 -200 B -550 -55 -55 -75 -75 -100 -100 OA:A OA: B OB:A : Indifferent