Economies began in d) ancient times, with the Sumer and Babylonians starting trading, etc.
Answer:
A The military leaders freed the slaves that worked in the mine
Answer:
ITS C!! :) hope this helps
The correct answer is B) emergence of a written language
Unlike the other mentioned things, emergence of a written language did revolutionize Native American cultures. Everything else mentioned here was just there and completely normal as they were hunters and what not.