Rock Company purchased a depreciable asset for $600,000 on April 1, 2015. The estimated salvage value is $60,000, and the estimated total useful life is 5 years. The straight-line method is used for depreciation. What is the balance in accumulated depreciation on May 1, 2018 when the asset is sold?

a. $234,000

b. $252,000

c. $297,000

d. $333,000