Which of these sentences from the Gettysburg address best supports the answers to Part A. * a- four score and seven years ago our father brought forth on this continent a new nation, conceived in liberty, and so dedicated to the proposition that all men are created equal.
* b- now we are engaged in a great civil war, testing whether that nation, or any nation so conceived and so dedicated, can long endure.
* c- we have come to dedicate a portion of that field, as a final resting place for those who have gave their lives that that nation might live.
* d- it is altogether fitting and proper that we should do this

The Part A discussed the idea of freedom.

Therefore, the sentence from the Gettysburg address that best supports the answers to Part A is:

* a- four score and seven years ago our fathers brought forth on this continent a new nation, conceived in liberty, and so dedicated to the proposition that all men are created equal.

Explanation:

The above sentence supports the central idea of freedom, especially for the slaves.  It was for their emancipation that the civil war was fought.  Emancipation connotes freedom and the sense that "all men are created equal."  The above remark was the opening sentence of President Abraham Lincoln's short address at Gettysburg, Pennsylvania on November 19, 1863.  The occasion was the dedication of the burial ground of soldiers who lost their lives fighting for freedom.

the anecdote makes readers feel sorry for the man’s lack of heritage, then reminds readers that the man has an equally valuable heritage.

we need to see the document to answer the question