Suppose the economy is headed into a period of uncertainty, credit rating agencies are reducing bond ratings for a treasury bond and an AAA/AA/BBB bond. What impact would you expect that assessment to have on yield to maturities calculated by the market?

a. Both yield to maturities would decrease

b. both yield to maturities would increase

c. I would expect the the AAA/AA/BBB YTM to decrease more than the treasury bond

d. I would expect the AAA/AA/BBB YTM to increase relative to the treasury bond