In February 2018, Gemstone Industries purchased the Opal Mine at a cost of $20,000,000. The mine is estimated to contain 500,000 carats of stone and to have a residual value of $1,000,000 after mining operations are completed. During 2018, 50,000 carats of stone were removed from the mine and sold. In this situation:

A. The book value of the mine is $19,000,000 at the end of 2018.

B. The amount of depletion deducted from revenue during 2018 is $1,900,000.

C. The amount of depletion deducted from revenue during 2018 is $1,000,000.

D. The mine is classified as an intangible asset and amortized over a period not to exceed 40 years.