5. In 2021 , the city of Dayton offered a $100 tax-exempt bond with a 3.3% annual coupon and 10 years to maturity. The bond sold for 103.8. The bond was callable as follows: 4 years at 102, 5 years at 101.2, 6 years and forward at 100.8. The call feature is exercisable at the end of each year. The structure of yields on comparable debt as of the day of offer is shown below. a. Does the callable bond product higher or lower returns than the comparable bonds? b. What are the implications of your calculations