The answer is "The emphasis of the speech stays on Wiesel's frightening experiences as a child." Wiesel's use of the first person allows him to give a more individual view of the story as a whole. These are his knowledges, they are not neutral because this is his story. The first person is the finest way for him to deliver the things he needs to tell, and the third person would have through the story more universal not personal.
so A) The audience can focus on Wiesel's terrible childhood experience