The total book value of equity of ABC Inc. is $5 million and book value per share is $10. The stock currently sells for $17.00 per share. The firm's bonds have a par value of $2.35 million and currently sell at 121% of par. The yield to maturity on the bonds is 7.50% and the firm's tax rate is 40%. What proportion of the firm is financed with debt? (No Excel answers please).

a. 25.07%

b. 15.04%

c. 8.57%

d. 28.33%

e. 10.03%