Which of these bonds is better and why, from the shareholder perspective?

a) $100 million bond (at par) maturing 5 years from today. The interest rate is 5% per year. Corporate tax rate is 35%. Assume the appropriate discount rate for the bond is 6%.

b) $100 million perpetuity bond (at par). Interest rate 2,5% per year. Proper discount rate is 10%