Stephen is comparing two mortgage options for his $80,000 mortgage. mortgage a: 15 years at 4.5% with monthly payments of $611.99and a total payback of $110,158.20. mortgage b: 30 years at 4% with monthly payments of $381.93and a total payback of $137,494.80. which option requires more interest to be paid over the life of the mortgage? how much more?