When did activities ocurr that demonstrate americans belief in manifest density?

The activities that demonstrate American's belief in Manifest Destiny happened in the 19th century. The term "manifest destiny" originated in the 1840s. It was the widely held belief that the US expansion was justifiable and inevitable. i think i just grabbed this off google tbh trying to help

answer; ///i do believe that the correct answer is (d); ///athens had a small population;

i believe the answer is a