A contractor has been awarded a project to construct a 3 miles long tunnel in a mountainous area. During the five-year construction period, the contractor will need water from a stream near the construction site. A pipeline system is required to convey the water to the construction site and you are asked to choose the best alternative from the following pipe sizes. The pump will operate 2000 hours per year. The pump and pipe's salvage values will cover only the cost of removal at the end of the five years. The lowest interest rate at which the contractor is willing to invest is 8%. Use the present worth method.. 2" 3" 4" 5" Installed cost of pipeline and pump $22,000 $23,000 $25,000 $30,000 Cost per hour for pumping $1.2 $0.65 $0.50 $0.40