In the last sentence of the Gettysburg address, President Lincoln is primarily appealing to:
D. Emotion
President Lincoln is appealing to the audience's emotions. This is reflected in his word choice. He is asking his audience to honor the dead by persevering in the cause so that they would not have died in vain. In other words, he is appealing to people's feelings by sending a message that giving up is the same as dishonoring those who fought for the cause. Also, he highlights the importance of those who died defending the cause. Finally, he uses the word "perish" to describe what would happen to the United States if they don't continue fighting.
"It is rather for us to be here dedicated to the great task remaining before us—that from these honored dead we take increased devotion to that cause for which they gave the last full measure of devotion—that we here highly resolve that these dead shall not have died in vain—that this nation, under God, shall have a new birth of freedom—and that government of the people, by the people, for the people, shall not perish from the earth"