Answer:
D.They comprised a large part of the membership of the Ku Klux Klan.
Step-by-step explanation:
The majority belonged to the Ku Klux Klan which was an organization of the late nineteenth century declared anti-Semitic, anti-black, anti-Catholic, anti-Masonic, anti-communist, homophobic and xenophobic, but deeply Protestant Christian, the theology of Ku Klux Klan is based on Protestantism of figures openly anti-Semites like Martin Luther.