Huffman Corporation constructed a building at a cost of $20,000,000. Average accumulated expenditures were $8,000,000, actual interest was $1,200,000, and avoidable interest was $800,000. If the salvage value is $1,600,000, and the useful life is 40 years, depreciation expense for the first full year using the straight-line method is $480,000. $490,000. $520,000. $680,000.