Barber, Inc., depreciates its building on a straight-line basis. A building was purchased on January 1 that had an estimated useful life of 20 years and a residual value of $20,000. The company’s Depreciation Expense for that year was $20,000 on the building. What was the original cost of the building?

a. $360,000

b. $380,000

c. $400,000

d. $420,000