can someone please explain this to me, thank you

A $10,000 investment in a 10-year T-bond that has a yield of 12.00% A $20,000 investment in a 10-year corporate bond with an A rating and a yield of 15.60% Based on this information, and the knowledge that the difference in liquidity risk premiums between the two bonds is 0.40%, what is your estimate of the corporate bond's default risk premium? 3.20% 0 4.80% O 4.48% 3.52%