Which statement best describes the Sumerian city-states?

a. Each had a written code of laws.

b. Each was located on the Tigris River.

c. Each was located in the mountains.

d. Each had its own government.

The correct option is D.

The Sumerian city state is made up of 12 large cities, which were governed separately by different rulers and each had its own government. The people of Sumerian are among the earliest civilized people, they organized themselves into different city states that were independent of one another. The cities are located at the southern side of Mesopotamia.