Final answer:
In the 1860 presidential election, John Bell received the most support in the border states, due to his moderate policies and appeal as a candidate for the Unionist faction. The correct answer is option a.
Step-by-step explanation:
In the 1860 presidential election, John Bell received the most support in the border states. The election showcased a deep sectional divide, with Abraham Lincoln and the Republican Party appealing to the northern electorate, and the Democrats splintered into factions. While John Breckinridge, another candidate, held sway in much of the southern states, John Bell's candidacy was particularly attractive to the border states, due in part to his moderate stance and efforts to reach out to other unionists.
Therefore, John Bell's support was strongest in the border states, reflecting a tentative middle ground between the polarized North and South. In the election, Abraham Lincoln emerged victorious without requiring a single Electoral College vote from the southern states, but John Bell captured some support in the areas that were neither strictly aligned with the North or the South—the border states.