please help me answer all of these questions thank you so much.

P6-26 (similar to) The following table summarizes the yields to maturity on several one-year, zero-coupon securities: Security Treasury Yield (%) 3.05 3.18 Armarate Security Treasury AAA corporate BBB corporate Yield (%) 3.05 3.18 420 Score: 0 of 1 pt 9 P 6-26 (similar to) BBB corporate B corporate 4.20 4.90 a. What is the price (expressed as a percentage of the face value) of a one-year, zero-coupon corporate bond with a AAA rating? b. What is the credit spread on AAA-rated corporate bonds? c. What is the credit spread on B-rated corporate bonds? d. How does the credit spread change with the bond rating? Why