B Company switched from the sum-of-the-years-digits depreciation method to straight-line depreciation in 2018. The change affects machinery purchased at the beginning of 2016 at a cost of $83,700. The machinery has an estimated life of five years and an estimated residual value of $4,185. What is B's 2018 depreciation expense? Multiple Choice $15,903 $21.204. $22.320 $10,602