You purchase a machine for $60,000, depreciated straight-line to a zero over its five year life. If the machine is sold at the end of the year four for $20,000, what are the after-tax proceeds from the sale, assuming your tax rate is 21%? A) $ 15,800 B) $18,320 C)$ 20,000 D) $ 9,300 E) $ 8000