The correct answer is C) Roosevelt's policies would attract African American voters.
What led South Carolinians to become suspicious of Franklin Roosevelt and his New Deal policies was that Roosevelt's policies would attract African American voters.
When Franklin D. Roosevelt became the President of the United States in 1933, one of the first things that he did was to create a series of programs called the "New Deal" in order to help poor American citizens that were affected due to the Great Depression that had started on October 29, 1929, after the US stock market crash, leaving millions of people without a job.
However, not all the states saw the New Deal with benevolence. In the case of white conservative people in Sout Carolina, they became suspicious of Franklin Roosevelt and his New Deal policies in that Roosevelt's policies would attract African American voters.