Help with Econ question

Four mutually exclusive alternatives, each with a useful life of 10 years, have been presented to the city council. Using an ERR analysis and MARR = 8%, which alternative would you recommend? The "do nothing" alternative is an option. Mutually Exclusive Alternatives 2 3 4 Initial Cost $4,000 $8,200 $5,500 $3,700 Annual Benefits 800 1,500 1,000 850 ERR 11.22% 10.23% 10.17% 12.78% 2