If a mining company extracts $1580000$ tonnes in a period but only sells $1190000$ tonnes,

depletion included in cost of goods sold is based on the $1580000$ tonnes extracted.

a separate accumulated depletion account is set up to record depletion on the $390000$ tonnes extracted but not sold.

accumulated depletion on the mine is based on the $1190000$ tonnes.

depletion included in cost of goods sold is based on the $1190000$ tonnes extracted and sold.