Equipment with a cost of $84,224, an estimated residual value of $5,514, and an estimated life of 10 years was depreciated by the straight-line method for 7 years. Due to obsolescence, it was determined that the remaining useful life should be shortened by 5 years and the residual value changed to zero. The depreciation expense for the current and future years is a. $55,097.00 b. $2,912.70 c. $2,427.25 d. $-14,563.50