Answer: People making choices based on their limited resources
Step-by-step explanation:
The option best describes the main behavior that economics studies is People making choices based on their limited resources.
Economics is a social science subject which studies how humans behaves due to scarcity and due to the limited resources that are available.
As a result of limited resources, Individuals or economic agents have to make choices and choose the good or service that matters most to them. This is where opportunity cost comes in as other options are left and the best option is chosen.