6-19. Six sites have been identified for a parking lot in downtown Blacksburg. Because the sites are plots of land, their salvage value and investment cost are identical. A 10-year study period has been specified, and the MARR is 18% per year. Which site should be chosen based on the IRR criterion? (6.4.2) ABC D E F Investment cost (thousands) $100 $150 $250 $400 $500 $700 Annual revenue minus expense (thousands) $15 $37.5 $50 $92.5 $112.5 $142.5 IRR on total investment 15% 25% 20% 23.1% 22.5% 20.4%