A company purchased a delivery truck on January 1, 2013, for $12,000. It is estimated that the delivery truck will have a $3,000 salvage value at the end of its 5-year useful life. If the company recorded depreciation expense of $2,880 for the year 2014 on the delivery truck, the depreciation method used by the company is a. not determinable. b. the straight-line method. c. the 150% declining balance method. d. the double-declining-balance method.