On January 1, Year 1, Li Company purchased an asset that cost $75,000. The asset had an expected useful life of five years and an estimated salvage value of $15,000. Li uses the straight-line method for the recognition of depreciation expense. At the beginning of the fourth year of usage, the company revised its estimated salvage value to $7,500. Based on this information, the amount of depreciation expense to be recognized at the end of Year 4 is:

A. 15,750 B. 12,000 C. 31,500 D. 19,500