Answer:
D. They grew rich as a result of the Delian League.
Step-by-step explanation:
The Delian league refers to an alliance between Greek States that were led by Athenians. In order to be a member of Delian League, a Greek City states need to pay the Athenians with a huge amount of money. In return , the Athenians will provide them with military's protection to prevent their traders from being raided by soldiers in Mediterranean region.
Many city states viewed that the amount of Monetary benefits that they get from trading safety surpassed the amount of money that they had to pay to the Athenians. As a result, Athenians Grew Rich because of the Delian league.