South Company purchased a machine for $180,000 on January 1, 2018. The machine is expected to have a four-year life, with a residual value of $20,000 at the end of four years. Using the sum-of-the-years-digits method, depreciation for 2018 and book value at December 31, 2018 would be? $72,000 and $108,000, $72,000 and $88,000, $64,000 and $116,000, $64,000 and $96,000