I believe the answer is: A social movement.
A social movement refers to a form of organized effort that aimed to address a specific social or political issues.
In general, these movement usually an effort to alleviate the suffering from a suppressed group that receive unfair treatment from the majorities.
It's a large alliance of nations, meant for the protection of themselves, I think.
Answer:
B
Explanation:
They thought it was safer to live in the desert so B would make sense
