Fourscore and seven years ago, our farthers brought forth on this continent an new nation, conceived in liberty, and dedication to the proposition that all men are created equal.

why does lincoln reference this portion of the declaration of independence in the gettysburg address

a. to show his appreciation for soldiers regardless of whether they fight for the north or south.
b. to encourage soldiers by bringing up a war that the uswon
c. to emphasize that the us was founded on the principle of freedom for all people.