Which theme from the Gettysburg Address is developed in these lines from the speech?

The world will little note, nor long remember what we say here, but it can never forget what they did here. 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.
   
A. Those who died did so without accomplishing anything. B. No one will remember the soldiers who died at Gettysburg. C. The living can honor the dead by continuing to do the work the dead began. D. The work soldiers began will never be finished.