Early in the current year, Tokay Co. purchased the Silverton Mine at a cost of $25,120,000. The mine was estimated to contain 240,000 tons of ore and to have a residual value of $4,000,000 after mining operations are completed. During the year, 225,000 tons of ore were removed from the mine. At year-end, the book value of the mine (cost minus accumulated depletion) is:

$21,120,000.

$5,320,000.

$19,800,000.

$17,120,000.