its 20 years, not four

2. The city administration is considering refurbishing the lighting system of its administraion building. After an initial investigation, the city procurement office has narrowed down the choices to the following two options: . Option 1 is an Ergolight system that costs $500,000 to purchase and install. The energy cost for option 1 is $20,000, and its maintenance cost is $2,000. 1. Option 2 is a conventional system that costs $100,000 to purchase and install. The energy cost for option 2 is $50,000, and its maintenance cost is $10,000. Both systems are expected to last for 26 years. Assume that the discount rate is 4% and all fiture costs are paid at the end of the year. Which lighting system should the city select based on LCC considerations