Please show the calculation and provide the asnwer ASAP.

A city council is analyzing three mutually exclusive alternatives, as systems to be acquired for a public project. Each system data, as far as benefits and costs and useful life are summarized in the below table. Which one of these three systems do you recommend to the city council using B-C ratio analysis? The interest rate is 7%. Initial investment, $ Annual O&M, $/year Benefits, $/year Disbenefits, $/year Salvage value, $ Useful life System 1 80,000 5500 80,000 20,000 5,000 4 System 2 90,000 10000 85,000 20,000 10,000 8 System 3 250,000 8000 60,000 40,000