单选题
An analyst does research about calculating relative yield spread and gathered the following yield information about two bonds:
| Issue | Yield |
| 5 year on-the-run Treasury | 5.10% |
| 5 year A-rated security | 6.35% |
The relative yield spread between these two bonds is closest to:
A. 4.5%
B. 19.7%
C. 24.5%