A cost that has already been paid, or the liability to pay has already been incurred, is a(n) :

A) Salvage value expense.
B) Net working capital expense.
C) Sunk cost.
D) Opportunity cost.
E) Erosion cost.

Sunk Cost

Costs that have already been incurred and cannot be recovered or changed, and thus should not affect future business decisions.

Salvage Value

The anticipated residual value of an asset after it has been fully depreciated and is no longer in use.

Net Working Capital

The variance between a corporation's current assets and its current debts, highlighting its short-term financial status.