One theme is perseverance. <span>Buck is determined to survive, but he also wants to be a leader. In order to do this, he has to complete hard tasks, kill certain things, and prove that he has the right qualities.</span>
A pure future is when you are certain of that what you’re are going to do
D is the correct answer. You can omit as many words as you want, as long as 'the meaning and spirit of the quote is retained', that is, the general sense you wanted to convey with that quote is still there, even after you deleted those several words.