When calculating an annual cash flow to be used as part of a capital budgeting analysis, why is the depreciation over a particular year first subtracted from the difference between project inflow and project outflow in that particular year, but is later added back in? A. Because it serves to increase the amount of tax the firm will have to pay B. Because it is not a real cash outflow but does create a tax deductible expense C. Because it has the unusual characteristic of switching signs in the middle of most projects D. Because it changes from negative to positive as the project moves forward E. Because it is an expense that can be immediately and fully deducted from revenues