a small manufacturing company is considering purchasing a maintenance contract for its air conditioning systems. since all of its systems are new, the company plans to begin the contract in year four and continue through year ten. the cost of the contract is $3,200 per year and the company's minimum attractive rate of return is 12% per year. the present worth of the contract is nearest to: a) $6,605 b) $10,395 c) $14,604 d) $18,081