On 1/1/17, MNO Inc purchased equipment for $220,000. At the time, the equipment had an estimated useful life of 10 years and an estimated salvage value of $10,000. The straight line depreciation method is being used. After 4 years, on 1/1/21, MNO realized that the equipment would only be useful for another 2 years after which it would be worthless. How much depreciation expense will be recorded in 2021 and 2022?

a) $68,000 b) $21,000 c) $52,500 d) $66,000