I'm assuming you are learning about the civil war. During this time, the Republican party was against slavery and was very popular in the north. In that case, it wouldn't be A or C. The Republicans during this time had no intention on rebuilding large plantations so it wouldn't be B. The answer is D, because most white southerners would only vote for the Republicans reform movements if they were against slavery, usually because the abolition of slavery would benefit them.
