Answer: B. The Assyrians
Step-by-step explanation:
The Hittite empire was a large one at its time and was able to conquer a significant part of Anatolia, Syria and the Northern areas of Mesopotamia. They brought with them changes to the Government of Mesopotamia and adopted many Mesopotamian practices as well.
Their influence was cut short however when the Assyrians fought to take control of Mesopotamia. It took several centuries to defeat them but the Assyrians finally managed in the 8th century BC.