Company purchases a building on January 1, 20219. The building has an estimated useful life of 25 years and a residual (salvage) value of $20,000. The company depreciates the building on a straight-line basis and records depreciation expense for 2019 of $20,000. What was the original cost of the building?

a. $460,000

b. $480,000

c. $500,000

d. $520,000