An economic expansion has caused Treasury yields to increase and absolute credit spreads to narrow. Which of the following is most likely true（）
A. Relative corporate yield spreads to Treasuries will have increased.
B. The yield ratio of BBB-rated bond yields to AAA-rated bond yields may have increased even as their absolute yield spread has decreased.
C. Even if absolute credit spreads had remained the same, the yield ratio and relative yield spread of BBB to AAA bonds could have decreased.
