What analysis method did Buff use when making this decision?

Buff Construction is building a new bridge. They have the option of using concrete or steel. See data: Cost of Construction Operations & Maintenance per Life year (in years) Concrete $50M $250,000 70 Steel $40M $500,000 50 i = 5% Buff decided to use steel for this bridge based on the following analysis: Concrete: 50M (A/P,5%,70) 0.05 + 0.25M 0.05 = $56.70M Steel: 40M (A/P,5%,50) + 0.5M 0.05 0.05 = $53.84M What analysis method did Buff use when making this decision? O Capitalized Cost Future Worth Replacement Analysis Benefit Cost Analysis