Bohm Company acquired equipment on January 1, 2017 which it depreciated under the straight-line method with an estimated life of fifteen years and no salvage value. On January 1, 2022, Bohm estimated that the equipment would only be used for six more years. How should this change be accounted for by Bohm? As a prior period adjustment As the cumulative effect of a change in accounting principle in 2022 By setting future annual depreciation equal to one-sixth of the book value on January 1, 2022 By continuing to depreciate the machinery over the original fifteen year life