The Gray Company purchased a new truck on January 1, 20XX. It cost him $ 24,000. Its useful life was estimated at 5 years and its residual value at $ 6,000. What is the balance of the Accumulated Depreciation account at the end of the second year if it were depreciated using the double-declining-balance method?

a.$ 11,520

b.$ 15,360

c.$ 3,840

d.$ 5,760