To improve package tracking at a UPS transfer facility, conveyor equipment was upgraded with RFID sensors at a cost of $100,000. The future market values are expected to decrease by 20% per year. The operating cost is expected to be $6,000 in year 1 with increases of $3,500 per year thereafter. At an interest rate of 8% per year, determine the economic service life of the sensor if the maximum life is 6 years. 5 years 4 years 3 years 6 years 1 year 2 years