D. He wants to show respect to the soldiers.
In his speech he talks about dedicating "a portion of that field as a final resting place for those who her gave their lives". The people who gave their lives are the soldiers. He continues by talking about how the soldiers have paid the ultimate sacrifice and their actions have consecrated the ground. This dedication will help the world to remember and honor the soldiers who lost their lives.
The passage does not have any indication of anger. It also doesn't suggest that he wants more people to join the fight or that he will take things further. This is simply about the soldiers who are buried in the battlegrounds.