All of these could be considered an "author's purpose". An author is technically anyone who writes anything, therefore the purpose of writing is theoretically limitless. If you have to choose one of these, however, it would be "to remind".
Interjections are basically exclamations such as: 'Ouch! Wow!', etc. So the correct answer is D, an exclamation point (!).
The answer is: Except for A) Researching the background of the author.
It is not necessary for you to know the background of the author for you to comprehend a memoir.
