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 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? \begin{tabular}{cc} Security & Yield (\%) \\ \hline Treasury & 3.11 \\ AAA corporate & 3.19 \\ BBB corporate & 4.25 \\ B corporate & 4.92 \\ \hline \end{tabular}