Which two factors caused boomers to encourage the federal government to open up the Unassigned Lands for non-American Indian settlement?A.The Unassigned Lands were crisscrossed by railroads and contained towns that already had been established.B.The Unassigned Lands contained promising farmland and were crisscrossed by railroads.C.The Unassigned Lands contained promising farmland and towns that already had been established.D.The Unassigned Lands potentially contained natural resources, and the federal government prohibited cattle drives.