Orion, a mining company in Canada, is considering a mining project that will have an initial cost of $25 million and generate revenues of $18 million per year for three years. During the fourth year, the mine will be shut down and there will be substantial clean-up costs to restore the land to its original state, (a process that will be completed during the fourth year.) Orion is also considering an alternative mining project which will cost $12 million and generate revenues of $6 million per year for four years but which does not involve clean-up costs. Orion's weighted average cost of capital is 12%. What must be the clean-up costs on the first project for Orion to be indifferent between the two projects? a) $24.1 million b) $18.26 million Od $12 million d) $15.6 million e) $17.12 million