A Mining Company's Extraction Costs Curve Is

A mining company's extraction costs curve is

A) upward-sloping because the more the company extracts, the more its marginal extraction costs increase.
B) upward-sloping because the more the company extracts, the more its marginal extraction costs decrease.
C) downward-sloping because the more the company extracts, the more its marginal extraction costs increase.
D) downward-sloping because the more the company extracts, the more its marginal extraction costs decrease.