The Exodusters' Westward Mass Migration Finally Faltered When

The Exodusters' westward mass migration finally faltered when

A) homesteading on the Great Plains proved more difficult than expected.
B) a massive, extended drought covered the Great Plains in in the late 1870s.
C) steamboat captains refused to transport more former slaves across the Mississippi.
D) white Kansans passed strict segregation laws.
E) the 13th, 14th, and 15th amendments to the Constitution were finally ratified.