Generally, opportunity costs increase and the production possibilities frontier bows outward. Why?

Question

Quizplus · Accepted Answer

Opportunity cost is the value of the next best alternative that must be forgone in order to pursue a certain action. Resources are not equally useful in all activities, meaning some resources are better suited for certain tasks than others. Therefore, when resources are allocated towards a specific activity, the opportunity cost of not using them in their best suited activity increases. As more and more resources are utilized, the opportunity cost increases, causing the production possibilities frontier to bow outward.

Generally, Opportunity Costs Increase and the Production Possibilities Frontier Bows