With Respect to Slavery, Lincoln at First ________, but Later

With respect to slavery, Lincoln at first ________, but later he ________.

A) was indifferent to the slavery issue; freed all slaves by executive order
B) worried about alienating the border states; proclaimed, as a military measure, that slaves in rebel areas were free
C) resisted any interference with the institution; reluctantly went along with Congress's initiative in ending slavery by constitutional amendment
D) lagged behind northern opinion, which strongly supported emancipation; urged Congress not only to end slavery but also to give blacks full social and political equality