Aperson had a choice between an apple or an orange. the person chooses the apple. what is the opportunity cost of choosing the apple?

a. there is no opportunity cost
b. the value of what was not chosen
c. the utility of the apple
d. the scarcity of oranges

(d) rivers.

explanation:

civilizations developed around rivers because their waters provided places to hunt and fish. also, as the rivers flooded, the lands around them became fertile. this allowed them to support farming. this is especially true of the nile river, which flooded the same time each year.

"they had a large area of land that they owned."