Problems facing settlers during the first Oklahoma land run included all of the

Problems facing settlers during the first Oklahoma land run included all of the following except _.
A.
a federal cavalry force that was too small to patrol the entire region
B.
sooners sneaking into the Unassigned Lands before the official time
C.
multiple claims on the same land, leading to disputes over land claims
D.
difficulty finding land claims that would have neighbors in the region