on january 1, 2022, woodstock, inc. purchased a machine costing $40,000. woodstock also paid $1,000 for transportation and installation. the expected useful life of the machine is 6 years and the residual value is $5,000. how much is the annual depreciation expense assuming use of the straight-line depreciation method?
a. $6,100.
b. $6,000.
c. $5,950.
d. $5,750.