Green Thumb's Greenhouse has the following cost of capital structure: Weight (Market Values Aftertax Cost Debt 60% 6.30% Preferred Shares 20% 9.20% Equity 20% 11.50% What is Green Thumb's Weighted Average Cost of Capital? Select one Ca. 7.45% b. 9.00% C. 7.92% O d. 8.70%