The correct answer is A.
Stephen A. Douglas (1813-1861) was an American politician and member of the House of Representatives. He became candidate for presidency in the election of 1860, compiting against Lincoln. He was known as the 'Little Giant' due to his short height but his dominant position in politics.
He believed in the principle of popular sovereignty, that the majority of citizens should decide on contendous matters such as the slavery issue. Otherwise, if the federal government enforces anti slave regulations, the detractor states and their people would issue unfriendly laws locally to ensure that discrimination continues. This is known as the Freeport Doctrine.
He also had mentioned explicitly his viewpoint about the Declaration of Independence, as a document not written for non-whites.