Marysa Corp. issued a $20-$year, $6$ percent semiannual bond $4$ years ago. The bond currently sells for $91$ percent of its face value. The book value of the debt issue is $$40$ million. In addition, the company has a second debt issue on the market, a zero coupon bond with $11$ years left to maturity; the book value of this issue is $$40$ million and the bonds sell for $59$ percent of par. The company's tax rate is $23$ percent.

a$.$ What is the company's total book value of debt? $($Do not round intermediate calculations and enter your answer in dollars, not millions of dollars, e$.$g$.,1,234,567.$

b$.$ What is the company's total market value of debt? $($Do not round intermediate calculations and enter your answer in dollars, not millions of dollars, e$.$g$.,1,234,567.$

c$.$ What is your best estimate of the aftertax cost of debt? $($Do not round intermediate calculations and enter your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$