Which of the Following Contributed to the Increased Economic and Military Power of the Sumerians?

Which of the following contributed to the increased economic and military power of the Sumerians?

A. the formation of alliances with other city-states
B. a series of highly strategic army leaders
C. the development of bronze to make weapons
D. a standing army of many trained soldiers

Correct answer is option C. The development of bronze to make weapons. Explanation: The development of bronze to make weapons are contributed to the increased economic and military power of the Sumerians.