What was a contribution of Darius I?

Please help. I need this grade.

Although Darius consolidated and added to the conquests of his predecessors, it was as an administrator that he made his greatest contribution to Persian history. He completed the organization of the empire into satrapies, initiated by Cyrus the Great, and fixed the annual tribute due from each province.

Explanation:

the navigation act prevented the colonies from exporting to countries other than britain and it prevented the importation of goods by other countries as well. so i believe the correct answer is d. other nations could not deliver goods to the colonies.

hope this .

answer; /// i believe that the correct answer is (d)the huang he river valley;