The fоllоwing dаtа аre fоr a series of increasingly extensive flood-control projects. Total Cost per Year Total Benefit per Year Plan A = Levees $ 10,000 $ 16,000 Plan B = Small Reservoir 24,000 36,000 Plan C = Medium Reservoir 44,000 52,000 Plan D = Large Reservoir 72,000 64,000 For Plan D marginal costs and marginal benefits are