Equipment with a cost of $88,847, an estimated residual value of $6,144, 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.$3,095.49

b.$-15,477.45

c.$2,579.58

d.$57,892.10