The correct answer is A) They all made it difficult or impossible for African American men to vote.
The three items on the list have in common the following: "They all made it difficult or impossible for African American men to vote."
It is true that the poll tax, the literacy test, and the grandfather clause were created to limit African Americans the possibility to vote in elections.
At the end of the Civil War, Congress passed the 14th Amendment to the United States Constitution that granted citizenship rights to former slaves and black people.
However, that could not be translated into the right o vote. The JimCrow laws and other southern legislation such as the Black codes limited the rights of African Americans.
People protested. marched, and discussed this issue. That's why Congress had to pass the 15th Amendment to the United States Constitution in 1870, which says that the right to vote for all citizens cannot be denied due to race, color, or social status.