Answer:
D-john C.breckinridge
Step-by-step explanation:
The candidate I believe most southern farmers would have voted for in the Presidential election 1860 is JOHN C. BRECKENRIDGE.
This is because John C. Breckinridge was widely known as someone or democrats who support proslavery.
He often criticizes that the federal government is without the jurisdiction to intervene on the issue of slavery in the country, including the nation's capital which is the District of Columbia.
Hence, based on the aforementioned and the fact that southern farmers are proslavery, therefore, most southern farmers would have voted for in the Presidential election 1860 is JOHN C. BRECKENRIDGE.