Beyond his role in leading the Israelites out of Egypt, what significant contribution did Moses make to the structure of Israelite society, as detailed in Exodus 18?

A He established a centralized monarchy to ensure unified rule. B He codified a comprehensive legal system based on Babylonian law. C He implemented a system of delegated authority with judges overseeing smaller groups, following Jethro's advice. D He instituted a series of annual festivals to promote national unity.