Final answer:
The correct answer is B: Abraham Lincoln (a) aligns with choice 2 (oppose the spread of slavery), Stephen Douglas (b) with choice 4 (popular sovereignty), John Breckinridge (c) with choice 1 (extend slavery into territories), and John Bell (d) with choice 3 (preserve the Union by compromise).
Step-by-step explanation:
The question asks to match each presidential candidate in the 1860 election with his party's position on the slavery question. During the chaotic 1860 presidential election, the views on slavery were sharply divided among the candidates:
- Abraham Lincoln (Republican Party) opposed the further spread of slavery into any U.S. territories, aligning him with choice number 2.
- Stephen Douglas (Northern Democratic Party) advocated for popular sovereignty—letting the residents of territories decide on slavery—which corresponds with choice number 4.
- John Breckinridge (Southern Democratic Party) supported extending slavery into the territories, which matches with choice number 1.
- John Bell (Constitutional Union Party) aimed to preserve the Union through compromise on the slavery issue, in line with choice number 3.
Therefore, the correct answer is B, which is a-2, b-4, c-1, d-3.