Answer: I would contend that the right answer is the D) Theme D because he focuses on this theme at the end of the speech.
Explanation: Just to elaborate a little on the answer, it can be added that by leaving that theme for the last part of his speech, Wyatt is showing that this is the part that he wants the audience to remember and recall best, since they will have that information fresh in their minds when they leave. Thanking the audience or using a personal story do not necessarily justify that those are the most important themes of the speech—he could just be using them to "break the ice" or win over his audience.