Why were the Ku Klux Klan and other White Supremacist organizations established during this period?

a.They were established to protect white women from being harmed by Freedmen
b.They were established primarily to intimidate and threaten African Americans to deter them from exercising their rights as new citizens.
c.They were established to protect the rights of white Southerners
d.They were established out of a sense of pride and bravery