Which european country took the lead in the exploration and colonization of africa, asia, and the americas in the early 1400s?

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.

the language dates from the contacts of arabian traders with the inhabitants of the east coast of africa over many centuries. under arab influence, swahili originated as a lingua franca used by several closely related bantu-speaking tribal groups.