A major cause of the Russian Revolution of 1917 was the a. defeat of Germany in the Russian campaign
b. marriage of Tsar Nicholas II to a German princess
c. existence of sharp economic differences between social classes
d. appeal of Marxism to the Russian nobility

existence of sharp economic differences between social classes

a. competition between france and england for land and power

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.