Which of the following techniques was used to prevent blacks from voting in the south during the late 19th century?

The end of the Civil War, the period of Reconstruction, and the 15th Amendment to the United States Constitution were attempts to protect the rights, including voting, of the ex-slaves, especially in the states of the defeated Confederacy. The first attempt involved threats, violence, and scare tactics. The development of the Ku Klux Klan, and other anti-black groups in the South, terrorized those ex-slaves who attempted to register or to vote. Black males who tried to vote were often fired from their jobs. Physical violence, such as beatings and lynching, also took place. New State laws were passed in the Southern states, following the end of Reconstruction, which tried to negate the purpose of the 15th Amendment. Literacy Tests were required in order to register, and the tests were made to prevent Blacks from passing. Grandfather Clauses were passed which prevented anyone from registering to vote unless their grandfathers had been eligible to vote. Descendants of slaves were thus denied the right to vote. Many states enacted poll taxes. Anyone who could not afford the tax (usually poor whites and Blacks) were denied the right to vote. With the threat of violence to the Black voter, or his family, and the fear of loosing a job, or the cost of paying the taxes, many Blacks simply gave up trying to vote and concentrated on trying to keep a job that would enable a family to survive the economic conditions in the south.