How can a religion spread from one area to another

Through countless conflicts, conquests, missions abroad, and simple word of mouth, these religions spread around the globe and forever molded the huge geographic regions in their paths.

Explanation:

a is correct

hope this let me know if it is right

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.