Answer:
Someone gives up going to see a movie to study for a test in order to get a good grade. The opportunity cost is the cost of the movie and the enjoyment of seeing it.
At the ice cream parlor, you have to choose between rocky road and strawberry. When you choose the rocky road, the opportunity cost is the enjoyment of the strawberry.
A player attends baseball training to be a better player instead of taking a vacation. The opportunity cost was the vacation.
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