A machine with a cost of $120,000 has an estimated residual value of $15,000 and an estimated life of 5 years or 15,000 hours. It is to be depreciated by the units-of-output method. What is the amount of depreciation for the second full year, during which the machine was used 5,000 hours?

a) $5,000

b)$45,000

c) $35,000

d) $21,000