Question

opportunity cost occurs because of a producers need to
limit resources.
protect resources.
allocate resources.
spend resources.

Explanation:

Opportunity cost is about choosing among alternatives. Producers have limited resources. When they allocate resources (decide how to use them), they forgo other uses. So, it occurs due to the need to allocate resources. For example, a producer allocating money to new machinery (opportunity cost is not using that money for more labor).

Answer:

C. allocate resources.