Martin Company purchases a machine at the beginning of the year at a cost of $72,000. The machine is depreciated using the straight-line method. The machines useful life is estimated to be 5 years with a $5,000 salvage value. Depreciation expense in year 4 is:

• $14,400.

• $13,400.

• $67,000.

• $57,600.

• $0.