Mullen Company purchased a new machine costing $55,200 on January 1, 2017. The machine is expected to have a $3,600 salvage value at the end of its useful life of six years. What is the depreciation expense that Mullen Company records for 2017 using the double-declining-balance method? 
 (A) $8,600 
 (B) $17,200 
 (C) $9,200 
 (D) $18,400