On January 1, 2012, Mill Corporation purchased for $750,000, equipment having a useful life of ten years and an estimated salvage value of $20,000. Mill has recorded depreciation of the equipment on the straight-line method. On December 31, 2019, the equipment was sold for $175,000. As a result of this sale, Mill should recognize a gain of Select one: a. $28,000. b. $9,000. c. $64,000. d. $0.