Sauer Milk Company is trying to determine its optimal capital structure The following options are under consideration: WEIGHTING COST OPTION A: Debt 20% 5% Preferred 10% 10% Common 70% 14% OPTION B: Debt 30% 5.5% Preferred 10% 10.5% Common 60% 15% OPTION C: Debt 40% 6% Preferred 10% 10.7% Common 50% 15.8% OPTION D: Debt 50% 8% Preferred 10% 11.2% Common 40% 17.5% Which of the plans has the lowest weighted average cost of capital?