The effective plan to disenfranchise southern blacks in the 1890s took its name from which state in which it first appeared?

The Mississippi Plan

Mississippi was the first state to enact laws preventing blacks from voting. Through literacy tests and poll taxes, blacks were prevented from voting because of cost and the inability to read. This system eventually evolved to include gerrymandering the districts to exclude blacks and primaries for whites only.

The policy of Mississippi spread to other southern states within twenty years. Each state used their own methods but the goal was all the same: prevent blacks from voting and/or holding government office. These laws continued in the US until the 1960's when the national government outlawed the practices.

Even though The Mississippi Plan was elaborated in 1875, it wasn't until 1890 when the state of Mississippi adopted a new constitution with which the black people were effectively disenfranchised.

In order to vote, the voters were required to pay a poll tax and pass a subjective literacy test which was applied by white administrators. These barriers weren't the only measures taken, since black people who tried to vote were victims of violence and fraud. This situation continued to happen until the black population stopped trying to exercise their rights.

Other southern states called it "The Mississippi Plan" and they quickly adopted it.

c or d both can be the answer