You can continue to use your less efficient machine at a cost of $8,000 annually for the next 5 years. alternatively, you can purchase a more efficient machine for $12,000 plus $5,000 annual maintenance. at a cost of capital of 15%, you should
a. purchase & save $600 in equivalent annual costs
b. purchase save $388 in equivalent annual costs
c. keep old machine and save $388 in equivalent annual costs
d. keep old save $580 in equivalent annual costs