a biography is a genre that mainly accounts somebody's life and that is written by somebody else. this genre supports sonia nazario's desire to share enrique's life because she can fully inform readers of his entire emotional journey.
in a biography, an author can share the readers almost everything about a person's life, or just one key event or personal aspect the author is interested in telling, like in this specific case in which sonia nazario is centered in enrique's emotional journey.