Answer:
The option which best describe the difference between "autobiography" and "memoir" is:
C. Memoir covers a particular time in the writer's life or recounts life events around one or two themes; autobiography covers the entire story of the author's life and has multiple themes.
Step-by-step explanation:
Both a memoir and an autobiography are a written account regarding someone's life written by that very person. However, there are differences between the two. An autobiography's purpose is to tell that person's whole story, since birth till now. The autobiography will not focus on one or two specific themes; instead, it will be broad, going from personal to professional life, from relationships to accomplishments, and so on.
On the other hand, a memoir will often develop only one or two themes throughout the book. Because of that, it may focus on a specific time in that person's life, or in multiple times in which the events are linked by that same theme. Let's take Elie Wiesel (1928-2016) as an example. The author was a survivor of the Holocaust in Germany. His memoir "Night" focuses precisely on that theme of surviving in a concentration camp. Facts and events in his life that are unrelated to that theme are not included in the story.