A homebuyer can obtain an $80,000 loan at 8.5% or obtain a $90,000 loan at 9%. The incremental cost of borrowing the additional $10,000 is 12.8%. Alternatively, a second loan for $10,000 can be obtained at 10%. What is the best alternative for obtaining the additional $10,000? Group of answer choices

a.) Borrow $80,000 at 8.5% and obtain a second mortgage for $10,000 at 10%.

b.)Borrow $90,000 at 9%.

c.) It is not worth borrowing the additional $10,000

d.) None of these