The Marginal Cost of Extraction of a Nonrenewable Resource Increases

The marginal cost of extraction of a nonrenewable resource increases with passage of time because:

A) the technology used in extraction depreciates in value.
B) the price of the product that uses this resource increases.
C) the exchange rate in the international market appreciates.
D) the tragedy of commons problem is encountered.
E) the resource gradually becomes scarce.