Westward expansion is defined as the us expanding to the land west of the original 13 a) tribes b) colonies c) states d) nations

Westward expansion is the expansion of the U.S. to the land west of the original 13 colonies. After the settlement of those colonies, American colonialists began to strike out in search of new land and resources. This expansion was fueled in later years by the Louisiana Purchase, Lewis & Clark expedition, and policy of "Manifest Destiny".

Answer might be b i think