You gather the following information on Costmart's financing

Market value of debt= 22,500,000

Book value of debt = $18,000,000

Pre-tax cost of debt= 6%

Cost Mart's beta= 1.4

Risk-free rate= 3%

Market risk premium= 8%

Shares outstanding= 1,000,000

Current share price-540

Book value of equity= 10,000,000

Tax rate= 40%

Which of the following is closest to the firm's WACC?

A) 11.25%

B) 6.83%

C) 7.42%

D) 10.4%