The Western Land Boom from 1791 to 1824 Resulted from All

The western land boom from 1791 to 1824 resulted from all of the following EXCEPT

A) the Land Act of 1820 and the development of inexpensive transportation to and through the Northwest and West.
B) land exhaustion in older tobacco states.
C) acute economic distress in the East during the embargo years prompted many Americans to settle in the West.
D) the frontier was pacified in the Northwest and South with the military defeats of the Indians.
E) the construction of railroad lines west of the Mississippi River.