Amemoir describes past events, but it is not considered a historical document. why?

a. because a memoir does not include many facts

b. because a memoir relates only the experiences of others

c. because a memoir relies largely on the writer's memories

d. because a memoir is not written by a historian

A memoir...is no considered a historical document. Why?

C. because a memoir relies largely on the writer's memories.

Although a memoir can take place in a historical setting, it is not a complete retelling of a historical event, but a narrative of a person's inner and individual experiences, recollections and perspectives on a particular moment in his/her life, and how these memories changed the author's life.  

The memories could have happened on a historical environment but they do not document in detail the context of the circumstances around the author, but his/her feelings and opinions and how he/she experienced said events.

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