A machine with a cost of $64,506 has an estimated residual value of $4,332 and an estimated life of 4 years or 16,401 hours. It is to be depreciated by the units-of-activity method. What is the amount of depreciation for the second full year, during which the machine was used 4,851 hours? Do not round your intermediate calculations. Oa. $15,043.50 Ob. $30,087.00 Oc. $17,797.94 Od. $19,079.24