Four different machines are under consideration for improving material flow in a certain production process. An engineer performed an economic analysis to select the best machine, but some of his calculations were erased from the report by a disgruntled employee. All machines are assumed to have a 7-year life. What is the value of A (the missing number by bold capital letters) in the report? Select one: a. +4,000 b. +3,000 c. +1,000 d. +2,000