(A) We have to promise to make this cemetery nice and remember these men.
(B) ** We need to promise that we will work on the great job ahead of us to remember the dead we will increase our effort to save the ideas that they died for.
EXPLANATIONS BELOW
Concept note-1: -The “unfinished work” to which Lincoln refers, “the great task remaining before us, ” is to put into practice the proposition to which this nation was and is dedicated: that all men are created equal. Miraculous though it was, the Constitution had left that work unfinished.
Concept note-2: -What is the unfinished work that those listening to the speech are asked to achieve? “It is for us the living, rather, to be dedicated here to the unfinished work which they who fought here have thus far so nobly advanced.