Asap how was imperialism a cause of world war i? a. efforts to stimulate trade increased tensions in european colonies. b. alliances among overseas territories increased tensions in europe. c. colonies' efforts to gain independence increased tensions in europe. d. rivalry over overseas territories increased tensions in europe.

B

Explanation:

because alliances were secret so all euro powers were entangled, also emergence of central power and emergence of allies

the answer to your question is a. the salt plains

in 1811, he led an expedition, known as the george c. sibley expedition, to improve relations with the pawnee and kansa tribes, and also to locate the rumored jefferson's salt mountain