Martin Company purchases a machine at the beginning of the year at a cost of $61,000. The machine is depreciated using the straight-line method. The machine’s useful life is estimated to be 5 years with a $7,000 salvage value. Depreciation expense in year 4 is:

a. $12,200.

b. $10,800.

c. $54,000.

d. $48,800.

e. $0.