Assume that interest rates on the following group of 20-year bonds are as follows: T-bond = 7.72% A=9.64% AAA-8.72% BBB - 10.18% All the bonds are non-callable. The difference in interest rates between the AAA and BBB bonds is caused by: A: Real risk-free rate differences. B. Maturity risk premium differences. C. Default risk differences. D. Liquidity risk differences E. Inflation risk premium differences. O a. Both A and B would contribute to the difference. O b. Both B and E would contribute to the difference. Oc. Both C and D would contribute to the difference. O d. Only option A would contribute to the difference. Oe. Only option E would contribute to the difference. A Moving to another question will save this response. 80 000 000 E4 ES F6