A machine with a cost of $65,000 has an estimated residual value of $5,000 and an estimated life of 5 years or 15,000 hours. It is to be depreciated by the units-of-production method. What is the amount of depreciation for the second full year, during which the machine was used 2,000 hours?

a. $8,000

b.$16,000

c.$21,667

d.$20,000