Cullumber Company bought equipment for $150000 on January 1, 2021. Cullumber estimated the useful life to be 5 years with no salvage value, and the straight-line method of depreciation will be used. On January 1, 2022, Cullumber decides that the business will use the equipment for a total of 6 years. What is the revised depreciation expense for 2022?
a. $30000
b. $12000
c. $24000
d. $20000