Which of the following statements is true? a) An asset impairment charge is required if the balance sheet value of an asset falls below the asset's fair value. b) Asset impairment charges can be used to raise future reported income. By writing down a fixed asset's depreciable cost now, there is a greater chance management will be able to write the asset back up in the future. Asset impairment charges can be used to raise previously reported income. The total depreciable cost of an asset is fixed. If the asset is written-down in the current period, depreciation expense in previous periods must be restated. d) By writing down a fixed asset's depreciable cost now through an asset impairment charge, there is less future depreciation expense to match against future revenues. e) None of these statements is correct. c)