The following table summarizes the yields to maturity on several one-year, zero-coupon securities:

a. What is the price (expressed as a percentage of the face value) of a one-year, zero-coupon corporate bond with an 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?

\begin{tabular}{cc} Security & Yield (%) \\ \hline Treasury & 3.09 \\ AAA corporate & 3.21 \\ BBB corporate & 4.21 \\ B corporate & 4.94 \\ \hline \end{tabular}