
Answer:
The $18 per unit is a:
sunk cost.
Explanation:
Chang's cost incurred per unit of $18 is a sunk cost. Â A sunk cost is a cost that has already been incurred. Â It does not make a difference in a future decision. This implies the Chang may decide to correct the defect or otherwise. Â What decision it takes should be based on the cost and revenue that results from the next decision, and not the past decision.