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 average cost of capital?