Equipment with a cost of $123,480, an estimated residual value of $5,880, and an estimated life of 14 years was depreciated by the straight-line method for 4 years. Due to obsolescence, it was determined that the remaining useful life should be shortened by 4 years and the residual value changed to zero. The depreciation expense for the current and future years is

 

A. $11,235

B. $33,600

C. $6,420 

D. $14,980