Although a number of things brought about world war 1 there was one event that pushed europe power the edge, what was that event ?

How did the discovery of gold impact american indian territory in the 1870s? a. war broke out among american indian groups when warring chiefs signed new treaties with the government. b. war broke out when white settlers pressured the government to take the land from american indians. c. war broke out when white settlers pressured the government to let american indians keep their land. d. war broke out when white settlers tried to buy land from warring american indian groups.