Suppose 10-year T-bonds have a yield of 4.30% and 10-year corporate bonds yield 8.15%. Also, corporate bonds have a 0.25% liquidity premium versus a zero liquidity premium for T-bonds, and the maturity risk premium on both Treasury and corporate 10-year bonds is 1.15%. What is the default risk premium on corporate bonds? a. 4.10% b. 3.60% c. 7.90% d. 4.55%