Schager Company purchased a computer system on January 1, 2014, at a cash cost of $25,600. The estimated useful life is 10 years, and the estimated residual value is $3,300. The company will use the double declining-balance depreciation method. How much is the 2015 depreciation expense?

A. $4,460.

B. $3,568.

C. $5,120.

D. $4,096.

Please provide as much math and/or detailed explanation as possible.