​The opportunity cost of an action:

A) ​is equal to the marginal cost of an action
B) is equal to explicit cost
C) is equal to the cost of the next best alternative forgone
D) ​is the total cost of an action

Opportunity Cost

The cost of forgoing the next best alternative when making a decision, representing the benefits that could have been received but were given up.

Explicit Cost

Direct, out-of-pocket payments for resources employed in the production of goods or services.

Marginal Cost

The additional cost incurred by producing and selling one more unit.