Area between the appalachia mountains and the mississippi river

The land west of the was thought to be worthless. Question 9 options: Mississippi River Appalachian Mountains ...

Americans of the Revolutionary Era regarded the "West" as those lands between the Appalachian Mountains and the Mississippi River. The area beyond the Mississippi was then largely unexplored and in the possession of foreign powers

answer; /// i believe that the correct answer is (b)///they gained vast amounts of

letter a is the answer