Read the following sentence and answer the question.

When President Lincoln delivered the Gettysburg Address, his purpose most likely was to increase support for the war, honoring the fallen Union soldiers, and emphasizing the importance of preserving the Union.

Which substitute for the underlined part of the sentence is the most effective in correcting its structure?

increasing support for the war, to honor the fallen Union soldiers, and emphasizing the importance of preserving the Union.
to increase support for the war, honor the fallen Union soldiers, and emphasize the importance of preserving the Union.
increasing support for the war, honoring the fallen Union soliders, and emphasize the importance of preserving the Union.
to increase support for the war, honor the fallen Union soldiers, and emphasizing the importance of preserving the Union.