The republicans believed it was a failure
The correct answer is a) caste.
In India, the division of kin groups in Jatis is not based on a specific principle, varying from ethnic origins to geographical occupation, exhibiting some variance. While the Jatis have not presented a fixed hierarchy, they present notions of a rank achieved over time considering lifestyle and social, political or economic status and considering the fact that the caste has a direct impact in these factors, we understand why it is the more relevant idea.
To buy expensive machinery
The Ku Klux Klan was created after Abraham Lincoln had claimed slavery was no longer legal. The KKK went around, killing black people and such. They also protested around the segregation process. They are still around to this day, but I don't believe that are killing anymore.