The correct answer is B) religious center.
What is an accurate description of a Mesopotamian ziggurat is "religious center."
Mesopotamian or Sumerian Ziggutarts were impressive buildings used as a ceremonial or religious center in old Sumerian times. This building was the predecesor or equivalent of pyramids in ancient Egypt times and other civilizations.
Let's remember that Sumeria was the oldest civilization known to man. Sumerians settled in the middle of the Tigris and Euphrates Rivers, in what today is Iraq in the Middle East. There, they established city-states.
These Ziggurats were the center of powerful Sumerian city-states such as Nippur, Eridu, Ur, Lagash, Kish, or Uruk.