What devices did people use to communicate with each other

I may be wrong but

Explanation:

In these times, the use of fire, smoke, and horns were effective ways for groups or individuals to communicate the need for assistance or to share information about important events. Smoke signals were especially useful as a tracking tool.

Or

Ink and paper but got the top answer from Internet

d is the answer. leo should include the source.

either b) they were often feared and despised by other native cultures. or

c) their obsession allowed them to coexist with many other native cultures because of their peaceful nature.