Bosio Inc.’s perpetual preferred stock sells for $85.00 per share

Bosio Inc.’s perpetual preferred stock sells for $85.00 per share and it pays an $8.50 annual dividend. If the company were to sell a new preferred issue it would incur a flotation cost of 4.00% of the price paid by investors. What is the company’s cost of preferred stock for use in calculating the WACC?