On April 10, 2019, Rio Corp. purchased machinery for $180,000. Residual value was estimated at $4,000. The machinery will be depreciated over ten years using the straight-line method. If depreciation is calculated on the basis of the nearest full month, the related Accumulated Depreciation account at December 31,2020will be

$31,500.

$30,800.

$30,000.

$29,333.