Who were the ‘Border Ruffians’? People who wanted to settle the frontier far to the west.
A group of men and women who were against slavery and used any means possible to stop it.
Politicians from Kansas who used violence to get their way.
Hostile men who came from Missouri to Kansas to illegally stuff the ballots.

C

Explanation:

to protect the united states' role as a world leader, president truman wanted to prevent the soviet union from spreading communism beyond its post-world war ii boundaries. he declared that the united states must assist any nations struggling to prevent a communist takeover.

i think the answer is c, rivers.

explanation:

sometimes, borders fall along natural boundaries like rivers or mountain ranges. for example, the boundary between france and spain follows the crest of the pyrenees mountains. for part of its length, the boundary between the united states and mexico follows a river called the rio grande. the borders of four countries divide africa’s lake chad: niger, chad, cameroon, and nigeria.