Answer:
D. a written system of language
Step-by-step explanation:
AN oracle bone were pieces of bones commonly ox and turtles that were used in ancient China to make predictions and divinations on the future, it was a common use of the Chinese people on this period of time to write symbols on the bone and then put it into a fire, to see how the bone will crack and wherever the bone cracked that would be the fate of the person that they were trying to predict the future of, this was a common practice and it is believed that helped develop the written system of language.