Are currently known as the world's oldest civilization.

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.

question:  

the chart compares religious beliefs to us political party support.

religious beliefs and party support, 2012

this chart demonstrates that

a) more highly religious people supported the republican candidate, while more nonreligious people supported the democratic candidate.

b) more highly religious people supported the democratic candidate, while more nonreligious people supported the republican candidate.

c) more moderately religious people supported the republican candidate, while more nonreligious people supported the democratic candidate.

d) more moderately religious people supported the democratic candidate, while more nonreligious people supported the republican candidate.

answer: a.