galvatron metals has a bond outstanding with a coupon rate of 6.4 percent and semiannual payments. the bond currently sells for $1,912 and matures in 16 years. the par value is $2,000 and the company's tax rate is 21 percent. what is the company's aftertax cost of debt? multiple choice 4.72% 4.11% 3.20% 3.43% 5.42%