Answer :
"(4) uniting the Ottoman Empire under an efficient government structure" would be the best answer, but of course this is a slightly objective question and answer.
(4) uniting the Ottoman Empire under an efficient government structure
The reign of Suleiman the Magnificent is considered the peak of the Ottoman Empire.
Suleiman was able to organize the vast empire using bureaucratic methods. Under Suleiman laws were clarified with the use of advisers and government officials. Laws were created to provide the vast empire with consistency as well as stability after conquest.