What was the name of the belief that it was god's plan for the us to own most or all of north america
a. expansionism
b. social darwinism
c. manifest destiny
c. popular sovereignty

It was the idea of "Manifest Destiny" that was the belief that it was God’s plan for the United States to own most or all of North America, since people thought the US was "destined" to occupy all the territory from the Atlantic to the Pacific. 

Manifest destiny was the belief that it was gods plan for the us to expand westward.