Which. Of the following was a characteristic of Aztec civilization

A. Cities were built on mountain tops
B. Slaves were often traded
C. Slavery was common
D.. cities were self governing

A. Cities were built on mountain tops

The correct answer is C. Slavery was common.

The characteristic of Aztec civilization that is mentioned in the options is:

C. Slavery was common.

To find the correct answer, we can evaluate each option:

A. Cities were built on mountain tops: While the Aztecs built their city, Tenochtitlan, on an island in Lake Texcoco (which provided some natural defenses), it was not built on a mountain top. Therefore, option A is not the correct answer.

B. Slaves were often traded: During the time of the Aztecs, slavery was indeed a prevalent practice. Slaves were acquired through various means, including as a result of war, debt, or as tribute from conquered territories. Slavery played a significant role in their economy and society, so option B accurately represents a characteristic of Aztec civilization.

C. Slavery was common: This statement is similar to option B, as both options refer to the prevalence of slavery in Aztec society. Therefore, option C is a correct characteristic of Aztec civilization.

D. Cities were self-governing: While the Aztec empire did consist of a centralized government led by an emperor and a council of nobles, the individual cities within the empire were not entirely self-governing. They were subject to the authority of the empire and its rulers. Therefore, option D is not the correct answer.

In conclusion, the correct characteristic of Aztec civilization mentioned in the options is:

C. Slavery was common.