If you could answers both A and B that would be greatly appreciated!

thank you

Avicorp has a $14.5 million debt issue outstanding, with a 6.2% coupon rate. The debt has semi-annual coupons, the next coupon is due in six months, and the debt matures in five years. It is currently priced at 94.45% of par value. a. What is Avicorp's pretax cost of debt? b. If Avicorp faces a 28% tax rate, what is its after-tax cost of debt? Note: Assume that the firm will always be able to utilize its full interest tax shield