I'd say that D is the right answer.
*You control your own destiny.*
Two lines of the poem directly support this claim. They are...
"I am the master of my fate:
I am the captain of my soul."
Meaning that the ultimate determining factor is you. Everyone is granted a choice, fate and destiny do not control you, because everyone has free-will.
The part of the excerpt from the Gettysburg in which Abraham Lincoln argue that the outcome of the war will depend on the determination and loyalty of northern citizens would be : ‘The brave men, living and dead, who struggled here, have consecrated it, far above our poor power to add and detract.
