Answer:
The correct answer is A
Step-by-step explanation:
Sunk cost is the cost which is incurred by an entity and that can no longer be recovered. It is that cost which is not considered when making the decision to continue investing in the online project as it cannot be recovered.
In this case, city of Tustin incurred $10 million on the project for building a new community college and further it require $40 million to finish the project. The economist told the city council to ignore $10 million because it is a sunk cost which cannot be recovered.