Answer:
B) Manifest destiny.
Explanation:
The Manifest Destiny is a concept, arduously followed in the 19th century, that sees it´s the right, the natural destiny of the United States to expand accross the continent until the shores of the Pacific. Such an outcome is God´s will, as geography, circumstances and history all favor the United States. It was a major drive of expansion for a good part of the century until it was fulfilled with victory in the Mexican-American War and the territories taken from Mexico.