The correct answer is: A.
A memoir ( from French memory ) is a collection of memories that an individual writes about moments or events that took place in his/her life. The events are supposed to be true. A memoir usually tells a story from a particular period of the author's life, as opposed to a biography that tells a story of a life.
In a memoir, the writer is the main character since the described story is the one he/she experienced themselves. Most memoirs are written in the first person, making it a very personal form of writing. A memoir gives the reader a glimpse into the author's feelings, opinions and thoughts.