The correct answer is (C) Southern whites.
The Southern strategy developed by Nixon was focused on gaining by Southern white voters by:
1) Appealing to those who were not in favor of federal policies like the intergration of black and white schools- Nixon used the resentment that some Southern whites had against the integration of public facilties and schools as a way to rally support for his presidency.
2) Advocating for a policy of states' rights- This strategy was focused on having the federal government being less involved with the decisions/institutions of each state. This was seen favorably by many white Southerners.