Which of the following factors made World War I a unique conflict? A. Great powers in Europe had never fought in a war against each
other before.
B. Countries from all over the world were pulled into the war through
systems of alliances.
C. Colonies of European countries refused to send soldiers to
support the war effort.
D. It was the first major war in Europe that didn't involve civilian
casualties.

Countries from all over the world were pulled into the war through

the answer is b: the religion they practice.

here's why:

there were many different native american tribes and those with similar characteristics formed a main tribe or nation. each had its own language, religion and customs.

i think it was because of how protected egyptian civilization was was which allowed them to evolve without much outside influence.