The Republican party became strong in the South, in part because millions of Southern African American men became voters. The correct option among all the options that are given in the question is the first option or option "A". I hope that this is the answer that has come to your great help.
The Republican Party became strong in the South due to the Southern Strategy of the Party in the late 1960s and early 1970s.
As the Civil Rights Era gained steam, many Southern Democrats felt betrayed by Lyndon Johnson and other Democrats who supported the Civil Rights movement.
The Republican Party moved to bring in these disaffected Democrats by focusing on strengthening states rights, as a way to induce segregationists to join the Republican party.
