What was Abraham Lincoln's concern about the Supreme Court's Dred Scott decision? that it would make slavery legal across the nation that it would lead to the direct election of senators that it would lead to the abolition of slavery C that the Republican Party would not support it

The question is asking about Abraham Lincoln's concern regarding the Supreme Court's Dred Scott decision. The Dred Scott decision was a landmark decision by the United States Supreme Court in 1857, which held that African Americans, whether enslaved or free, could not be American citizens and therefore had no standing to sue in federal court. The decision also declared that the federal government had no power to regulate slavery in the federal territories acquired after the creation of the United States. Lincoln was concerned that this decision would make slavery legal across the nation, which is why option A is the correct answer. The other options do not accurately reflect Lincoln's concerns about the Dred Scott decision.